# FILE: https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/index.md
---
{
"id": "absinth-wormwood",
"name": "Absinth wormwood",
"scientific": "Artemisia absinthium",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Ingestion toxicity and skin irritation",
"warning_tone": "danger",
"aliases": [
"absinthe",
"wormwood"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-artemisia-absinthium",
"S27",
"Fremont-list-definitions"
],
"description": "Absinth wormwood: Ingestion toxicity and skin irritation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-artemisia-absinthium"
],
"scope": "Species-specific",
"note": "",
"id": "absinth-wormwood-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-artemisia-absinthium"
],
"scope": "Species-specific",
"note": "",
"id": "absinth-wormwood-2"
},
{
"label": "People",
"sources": [
"N-artemisia-absinthium"
],
"scope": "Species-specific",
"note": "",
"id": "absinth-wormwood-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "absinth-wormwood-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "absinth-wormwood-5"
},
{
"id": "absinth-wormwood-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"absinth-wormwood-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"absinth-wormwood-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/absinth-wormwood.md"
}
---
# Absinth wormwood
*Artemisia absinthium*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Ingestion toxicity and skin irritation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**young foliage** — Dense young growth with deeply divided gray-green leaves, viewed from above.
Photo: Agnieszka Kwiecień, Nova; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_absinthium_Bylica_pio%C5%82un_2021-05-14_02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f3/Artemisia_absinthium_Bylica_pio%C5%82un_2021-05-14_02.jpg). Source-identified photograph with visual consistency check Absinthium ( Artemisia absinthium ), plant cultivated in Wrocław University Botanical Garden, Wrocław, Poland. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Upright silvery, bushy wormwood with divided leaves growing in grassland.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_absinthium_sl2.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1f/Artemisia_absinthium_sl2.jpg). Source-identified photograph with visual consistency check Habitus Taxonym: Artemisia absinthium ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Kranberg bei Ziersdorf, district Hollabrunn, Lower Austria - ca. 350 m a.s.l. Habitat: semi-dry grassland Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**reproductive stems** — Tall reproductive stems rising above broad divided lower leaves in bare, dry soil.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_absinthium_sl5.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/89/Artemisia_absinthium_sl5.jpg). Source-identified photograph with visual consistency check Habitus Taxonym: Artemisia absinthium ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: semi-dry grasslands and wine yards to the north of Oberthern, municipality Heldenberg, district Hollabrunn, Lower Austria - ca. 300 m ü. A. Habitat: rein Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Aromatic, silver-gray, finely divided leaves and small, drooping yellow-green flowerheads on a perennial. [N-artemisia-absinthium](https://plants.ces.ncsu.edu/plants/artemisia-absinthium/)
## Plants & habitat
Escapes cultivation into disturbed sites and spreads by seed. Colorado’s designation applies despite ornamental or historical beverage uses. [N-artemisia-absinthium](https://plants.ces.ncsu.edu/plants/artemisia-absinthium/)
## People
Thujone-containing plant material can cause serious poisoning when overused; contact dermatitis is also reported. This guide does not recommend medicinal or food preparation. [N-artemisia-absinthium](https://plants.ces.ncsu.edu/plants/artemisia-absinthium/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-artemisia-absinthium** — [artemisia absinthium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/artemisia-absinthium/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=absinth-wormwood) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| absinth-wormwood-1 | Recognize | Species-specific | N-artemisia-absinthium | No quantitative safe exposure established here. |
| absinth-wormwood-2 | Plants & habitat | Species-specific | N-artemisia-absinthium | No quantitative safe exposure established here. |
| absinth-wormwood-3 | People | Species-specific | N-artemisia-absinthium | No quantitative safe exposure established here. |
| absinth-wormwood-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| absinth-wormwood-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md
---
{
"id": "african-rue",
"name": "African rue",
"scientific": "Peganum harmala",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Highly poisonous if eaten; deep-rooted invader",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"NPS-african",
"WA-african-rue",
"S27",
"Fremont-list-definitions"
],
"description": "African rue: Highly poisonous if eaten; deep-rooted invader. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"NPS-african"
],
"scope": "Species-specific",
"note": "",
"id": "african-rue-1"
},
{
"label": "Plants & habitat",
"sources": [
"NPS-african",
"WA-african-rue"
],
"scope": "Species-specific",
"note": "",
"id": "african-rue-2"
},
{
"label": "People",
"sources": [
"NPS-african"
],
"scope": "Species-specific",
"note": "",
"id": "african-rue-3"
},
{
"label": "Dogs & cats",
"sources": [
"NPS-african"
],
"scope": "General animal warning; pet thresholds unknown",
"note": "",
"id": "african-rue-4"
},
{
"label": "Other animals",
"sources": [
"NPS-african"
],
"scope": "General animal warning",
"note": "",
"id": "african-rue-5"
},
{
"id": "african-rue-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/african-rue.md"
}
---
# African rue
*Peganum harmala*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Highly poisonous if eaten; deep-rooted invader.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — A partly open white flower above narrow, deeply divided leaves.
Photo: Alex Abair; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/15127830); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/22606152/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit** — A dry, opened capsule with brown seeds visible inside.
Photo: Alex Abair; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/15127830); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/22606149/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A dense, rounded green plant growing in bare, dry soil.
Photo: Alex Abair; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/15127830); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/22606147/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Bright green, branching stems carry divided, narrow leaves and small white flowers with five petals. [NPS-african](https://www.nps.gov/whsa/learn/nature/africanrue.htm)
## Plants & habitat
Deep roots, drought tolerance and plentiful seeds allow invasion of disturbed dry ground. Root fragments can sprout. [NPS-african](https://www.nps.gov/whsa/learn/nature/africanrue.htm) [WA-african-rue](https://www.nwcb.wa.gov/weeds/african-rue)
## People
The National Park Service describes ingestion as highly toxic. Do not taste or use this plant as a home remedy. [NPS-african](https://www.nps.gov/whsa/learn/nature/africanrue.htm)
## Dogs & cats
The source warns of animal poisoning broadly; it supplies no dog- or cat-specific dose. Keep pets from eating plants or seeds. [NPS-african](https://www.nps.gov/whsa/learn/nature/africanrue.htm)
*Evidence scope: General animal warning; pet thresholds unknown.*
## Other animals
Ingestion is a serious animal-poisoning concern. Seek veterinary advice after suspected exposure. [NPS-african](https://www.nps.gov/whsa/learn/nature/africanrue.htm)
*Evidence scope: General animal warning.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **NPS-african** — [African Rue](https://www.nps.gov/whsa/learn/nature/africanrue.htm), US National Park Service. Accessed 2026-09-07T01:21:13+00:00. Locator: Species identity, description, ecology and exposure evidence.
- **WA-african-rue** — [African rue](https://www.nwcb.wa.gov/weeds/african-rue), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:18:56+00:00. Locator: Species or hybrid identity, description and ecology.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=african-rue) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| african-rue-1 | Recognize | Species-specific | NPS-african | No quantitative safe exposure established here. |
| african-rue-2 | Plants & habitat | Species-specific | NPS-african, WA-african-rue | No quantitative safe exposure established here. |
| african-rue-3 | People | Species-specific | NPS-african | No quantitative safe exposure established here. |
| african-rue-4 | Dogs & cats | General animal warning; pet thresholds unknown | NPS-african | No quantitative safe exposure established here. |
| african-rue-5 | Other animals | General animal warning | NPS-african | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/african-rue/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/index.md
---
{
"id": "annual-sowthistle",
"name": "Annual sowthistle",
"scientific": "Sonchus oleraceus",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Windborne seed and crop-pest hosting",
"warning_tone": "caution",
"aliases": [
"common sowthistle",
"smooth sowthistle"
],
"taxonomy_note": "Separate from prickly sowthistle (Sonchus asper) and the root-spreading perennial sowthistle (Sonchus arvensis). Seedlings can be difficult to separate.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"U-sowthistle",
"S27"
],
"description": "Annual sowthistle: Windborne seed and crop-pest hosting. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"U-sowthistle"
],
"scope": "Species-specific",
"note": "",
"id": "annual-sowthistle-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "annual-sowthistle-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "annual-sowthistle-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "annual-sowthistle-4"
},
{
"label": "Plants & habitat",
"sources": [
"U-sowthistle"
],
"scope": "Species ecology; location-limited pest examples",
"note": "",
"id": "annual-sowthistle-5"
},
{
"label": "Management & timing",
"sources": [
"U-sowthistle"
],
"scope": "Management inference from annual seed reproduction",
"note": "",
"id": "annual-sowthistle-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"annual-sowthistle-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"annual-sowthistle-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"annual-sowthistle-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 80; Sonchus oleraceus",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Sonchus oleraceus"
},
"source": "content/plants/annual-sowthistle.md"
}
---
# Annual sowthistle
*Sonchus oleraceus*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Windborne seed and crop-pest hosting.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Separate from prickly sowthistle (Sonchus asper) and the root-spreading perennial sowthistle (Sonchus arvensis). Seedlings can be difficult to separate.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower head** — Close view of a pale yellow head composed of many narrow strap-shaped florets.
Photo: Miwasatoshi; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Sonchus-oleraceus-20080403.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/5/59/Sonchus-oleraceus-20080403.JPG). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Sow-thistles can overlap in appearance. Source identification is retained; the leaf and fruit views complement the flower view rather than independently proving identity. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf** — A deeply lobed middle leaf with a large pointed terminal lobe and toothed edges.
Photo: T.Voekler; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:S%C3%B3nchus_oler%C3%A1ceus_4562.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b7/S%C3%B3nchus_oler%C3%A1ceus_4562.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Sow-thistles can overlap in appearance. Source identification is retained; the leaf and fruit views complement the flower view rather than independently proving identity. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruits** — Several brown fruits with fine white pappus hairs photographed against a dark background.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Sonchus_oleraceus_15-p.bot-sonch.olera-19.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/91/Sonchus_oleraceus_15-p.bot-sonch.olera-19.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Sow-thistles can overlap in appearance. Source identification is retained; the leaf and fruit views complement the flower view rather than independently proving identity. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An upright annual with hollow stems, milky sap, yellow flower heads and fluffy seedheads. Upper leaves clasp the stem with pointed, clawlike basal lobes. [U-sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It occupies disturbed gardens and cropland and can host aphids and other crop pests. The cited examples are from California; they do not prove a particular Colorado pest outbreak. [U-sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/)
*Evidence scope: Species ecology; location-limited pest examples.*
## Management & timing
Prevent plants from producing and dispersing seed. Confirm the species before treating a recurring colony as annual sowthistle. [U-sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/)
*Evidence scope: Management inference from annual seed reproduction.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **U-sowthistle** — [Annual sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/), University of California Statewide Integrated Pest Management. Accessed 2026-09-07T02:26:10+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=annual-sowthistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 80; Sonchus oleraceus. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Separate from prickly sowthistle (Sonchus asper) and the root-spreading perennial sowthistle (Sonchus arvensis). Seedlings can be difficult to separate.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| annual-sowthistle-1 | Identification | Species-specific | U-sowthistle | No quantitative safe exposure established here. |
| annual-sowthistle-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| annual-sowthistle-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| annual-sowthistle-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| annual-sowthistle-5 | Plants & habitat | Species ecology; location-limited pest examples | U-sowthistle | No quantitative safe exposure established here. |
| annual-sowthistle-6 | Management & timing | Management inference from annual seed reproduction | U-sowthistle | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/index.md
---
{
"id": "big-sagebrush",
"name": "Big sagebrush",
"scientific": "Artemisia tridentata",
"category": "xeriscape",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Valuable native habitat; subspecies and pet evidence need care",
"warning_tone": "caution",
"aliases": [
"basin big sagebrush",
"mountain big sagebrush",
"Wyoming big sagebrush"
],
"taxonomy_note": "A broad Artemisia tridentata profile, not a key to its subspecies. The current three photographs are source-identified as subsp. vaseyana (mountain big sagebrush). They do not illustrate every subspecies. Culinary sage and Russian sage belong to different taxa.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"A-big-sagebrush",
"C-native-shrubs",
"S27"
],
"description": "Big sagebrush: Valuable native habitat; subspecies and pet evidence need care. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"A-big-sagebrush"
],
"scope": "Species-specific",
"note": "",
"id": "big-sagebrush-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "big-sagebrush-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "big-sagebrush-3"
},
{
"label": "Other animals",
"sources": [
"A-big-sagebrush"
],
"scope": "Species-specific",
"note": "",
"id": "big-sagebrush-4"
},
{
"label": "Plants & habitat",
"sources": [
"C-native-shrubs",
"A-big-sagebrush"
],
"scope": "Species-specific",
"note": "",
"id": "big-sagebrush-5"
},
{
"label": "Management & timing",
"sources": [
"C-native-shrubs",
"A-big-sagebrush"
],
"scope": "Landscape synthesis",
"note": "",
"id": "big-sagebrush-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"big-sagebrush-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"big-sagebrush-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 35; Artemisia tridentata",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Artemisia tridentata"
},
"source": "content/plants/big-sagebrush.md"
}
---
# Big sagebrush
*Artemisia tridentata*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Valuable native habitat; subspecies and pet evidence need care.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** A broad Artemisia tridentata profile, not a key to its subspecies. The current three photographs are source-identified as subsp. vaseyana (mountain big sagebrush). They do not illustrate every subspecies. Culinary sage and Russian sage belong to different taxa.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Mountain big sagebrush (Artemisia tridentata subsp. vaseyana) shrub with upright reproductive shoots beside a mountain pond.
Photo: Matt Lavin; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/307025284); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/553735381/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source explicitly identifies Artemisia tridentata subsp. vaseyana (mountain big sagebrush). These photographs represent that subspecies within the requested species. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**reproductive-shoots** — Close view of developing reproductive shoots and gray-green foliage of mountain big sagebrush (Artemisia tridentata subsp. vaseyana).
Photo: Matt Lavin; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/307025284); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/553735374/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source explicitly identifies Artemisia tridentata subsp. vaseyana (mountain big sagebrush). These photographs represent that subspecies within the requested species. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves** — Fuzzy gray-green, three-toothed leaves of mountain big sagebrush (Artemisia tridentata subsp. vaseyana).
Photo: Matt Lavin; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/307025284); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/553735433/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source explicitly identifies Artemisia tridentata subsp. vaseyana (mountain big sagebrush). These photographs represent that subspecies within the requested species. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An aromatic evergreen shrub with gray-green foliage, often with three small lobes at the leaf tip. Height, branching and flowering pattern vary substantially among subspecies. [A-big-sagebrush](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
An important winter food and cover plant for many wildlife species. Livestock use varies with plant chemistry and subspecies; wildlife browsing is not a safe feeding recommendation for pets. [A-big-sagebrush](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf)
## Plants & habitat
CSU includes it among native landscape shrubs for low-water sites. Natural sagebrush habitat supports many dependent animals; an unwanted garden seedling is a different management question. [C-native-shrubs](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/) [A-big-sagebrush](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf)
## Management & timing
Match the plant and subspecies to the site and avoid excessive moisture. Consider retaining established native habitat before removing shrubs. [C-native-shrubs](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/) [A-big-sagebrush](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf)
*Evidence scope: Landscape synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **A-big-sagebrush** — [Big sagebrush plant guide](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf), USDA Natural Resources Conservation Service. Accessed 2026-09-07T02:33:44+00:00. Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions.
- **C-native-shrubs** — [Native shrubs for Colorado landscapes](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/), Colorado State University Extension. Accessed 2026-09-07T02:33:44+00:00. Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=big-sagebrush) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 35; Artemisia tridentata. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
A broad Artemisia tridentata profile, not a key to its subspecies. The current three photographs are source-identified as subsp. vaseyana (mountain big sagebrush). They do not illustrate every subspecies. Culinary sage and Russian sage belong to different taxa.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| big-sagebrush-1 | Identification | Species-specific | A-big-sagebrush | No quantitative safe exposure established here. |
| big-sagebrush-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| big-sagebrush-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| big-sagebrush-4 | Other animals | Species-specific | A-big-sagebrush | No quantitative safe exposure established here. |
| big-sagebrush-5 | Plants & habitat | Species-specific | C-native-shrubs, A-big-sagebrush | No quantitative safe exposure established here. |
| big-sagebrush-6 | Management & timing | Landscape synthesis | C-native-shrubs, A-big-sagebrush | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md
---
{
"id": "bittersweet-nightshade",
"name": "Bittersweet nightshade",
"scientific": "Solanum dulcamara",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Poisonous berries and foliage",
"warning_tone": "danger",
"aliases": [
"climbing nightshade",
"woody nightshade"
],
"taxonomy_note": "Not interchangeable with deadly nightshade (Atropa belladonna), edible tomatoes or other Solanum species. County occurrence remains to be mapped in this guide.",
"source_ids": [
"CO-rules-2025",
"N-solanum-dulcamara",
"S27"
],
"description": "Bittersweet nightshade: Poisonous berries and foliage. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-solanum-dulcamara"
],
"scope": "Species-specific",
"note": "",
"id": "bittersweet-nightshade-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-solanum-dulcamara"
],
"scope": "Species-specific",
"note": "",
"id": "bittersweet-nightshade-2"
},
{
"label": "People",
"sources": [
"N-solanum-dulcamara"
],
"scope": "Species-specific",
"note": "",
"id": "bittersweet-nightshade-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-solanum-dulcamara"
],
"scope": "Species-specific",
"note": "",
"id": "bittersweet-nightshade-4"
},
{
"label": "Other animals",
"sources": [
"N-solanum-dulcamara"
],
"scope": "Species-specific",
"note": "",
"id": "bittersweet-nightshade-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/bittersweet-nightshade.md"
}
---
# Bittersweet nightshade
*Solanum dulcamara*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Poisonous berries and foliage.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Not interchangeable with deadly nightshade (Atropa belladonna), edible tomatoes or other Solanum species. County occurrence remains to be mapped in this guide.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Dense tangle of leafy scrambling stems with pointed green leaves.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Solanum_dulcamara_0001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1e/Solanum_dulcamara_0001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Purple flowers with reflexed petals and projecting yellow anther cones.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Solanum_dulcamara_0002.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b5/Solanum_dulcamara_0002.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit** — Hanging cluster of glossy oval red berries on purple-brown stalks.
Photo: Olli Salmela, ( Dacnoh ); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Solanum_dulcamara_fruits.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b0/Solanum_dulcamara_fruits.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A scrambling perennial with purple flowers, a prominent yellow anther cone and berries that ripen red. Some leaves have small basal lobes. [N-solanum-dulcamara](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/)
## Plants & habitat
An introduced, spreading vine of moist disturbed places; it can climb over surrounding vegetation. [N-solanum-dulcamara](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/)
## People
All parts are poisonous, including attractive berries. Ingestion can cause gastrointestinal and neurological illness; contact may irritate skin. [N-solanum-dulcamara](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/)
## Dogs & cats
NC State flags both dogs and cats. Prevent chewing or berry consumption and seek veterinary advice for exposure. [N-solanum-dulcamara](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/)
## Other animals
The source also identifies a livestock concern. Do not treat the plant as forage. [N-solanum-dulcamara](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-solanum-dulcamara** — [solanum dulcamara — Plant Toolbox](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=bittersweet-nightshade) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Not interchangeable with deadly nightshade (Atropa belladonna), edible tomatoes or other Solanum species. County occurrence remains to be mapped in this guide.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| bittersweet-nightshade-1 | Recognize | Species-specific | N-solanum-dulcamara | No quantitative safe exposure established here. |
| bittersweet-nightshade-2 | Plants & habitat | Species-specific | N-solanum-dulcamara | No quantitative safe exposure established here. |
| bittersweet-nightshade-3 | People | Species-specific | N-solanum-dulcamara | No quantitative safe exposure established here. |
| bittersweet-nightshade-4 | Dogs & cats | Species-specific | N-solanum-dulcamara | No quantitative safe exposure established here. |
| bittersweet-nightshade-5 | Other animals | Species-specific | N-solanum-dulcamara | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md
---
{
"id": "black-greasewood",
"name": "Black greasewood",
"scientific": "Sarcobatus vermiculatus",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Oxalate poisoning can be fatal to livestock",
"warning_tone": "danger",
"aliases": [
"greasewood"
],
"taxonomy_note": "Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"A-greasewood",
"F-sarcobatus",
"S27"
],
"description": "Black greasewood: Oxalate poisoning can be fatal to livestock. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"A-greasewood"
],
"scope": "Species-specific",
"note": "",
"id": "black-greasewood-1"
},
{
"label": "People",
"sources": [
"A-greasewood"
],
"scope": "Handling precaution inferred from structure",
"note": "",
"id": "black-greasewood-2"
},
{
"label": "Dogs & cats",
"sources": [
"A-greasewood"
],
"scope": "Contact precaution; pet toxicology unresolved",
"note": "",
"id": "black-greasewood-3"
},
{
"label": "Other animals",
"sources": [
"A-greasewood"
],
"scope": "Species-specific",
"note": "",
"id": "black-greasewood-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-sarcobatus"
],
"scope": "Species-specific",
"note": "",
"id": "black-greasewood-5"
},
{
"label": "Management & timing",
"sources": [
"A-greasewood",
"F-sarcobatus"
],
"scope": "Management synthesis",
"note": "",
"id": "black-greasewood-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"black-greasewood-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"black-greasewood-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 78; Sarcobatus vermiculatus",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Sarcobatus vermiculatus"
},
"source": "content/plants/black-greasewood.md"
}
---
# Black greasewood
*Sarcobatus vermiculatus*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Oxalate poisoning can be fatal to livestock.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Low, spreading greasewood shrub with dense green foliage in open dry ground.
Photo: John Gaskin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/184619764); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/322294640/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves-stem** — Close view of curved, fleshy green greasewood leaves along a pale woody twig.
Photo: John Gaskin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/184619764); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/322294623/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower-spikes** — Green, cylindrical greasewood flower spikes among narrow succulent leaves.
Photo: Dustin Snider; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/124972281); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/211886879/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A woody shrub of saline ground with stiff, thorn-tipped branches, narrow fleshy leaves and small pale flowers. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)
## People
Thorny branches are a contact hazard. Human ingestion safety has not been established in the reviewed material. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)
*Evidence scope: Handling precaution inferred from structure.*
## Dogs & cats
Avoid contact with sharp branches. Livestock oxalate findings do not establish a pet-specific dose or clinical outcome. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)
*Evidence scope: Contact precaution; pet toxicology unresolved.*
## Other animals
Rapid heavy consumption can cause fatal oxalate poisoning in sheep and cattle. Risk varies with season, plant chemistry and other forage; do not use this page to calculate a safe ration. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)
## Plants & habitat
A native component of saline basins, it provides wildlife cover and browse. Dense stands require ecological assessment, not automatic treatment as an introduced invader. [F-sarcobatus](https://research.fs.usda.gov/feis/species-reviews/sarver)
## Management & timing
Ask a range specialist to assess forage access and the saline site before treatment. Existing browse value does not justify feeding an untested amount. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/) [F-sarcobatus](https://research.fs.usda.gov/feis/species-reviews/sarver)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **A-greasewood** — [Greasewood (Sarcobatus vermiculatus)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/), USDA Agricultural Research Service. Accessed 2026-09-07T02:24:50+00:00. Locator: Identification, distribution and livestock poisoning; treatment instructions excluded.
- **F-sarcobatus** — [Black greasewood](https://research.fs.usda.gov/feis/species-reviews/sarver), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=black-greasewood) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 78; Sarcobatus vermiculatus. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| black-greasewood-1 | Identification | Species-specific | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-2 | People | Handling precaution inferred from structure | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-3 | Dogs & cats | Contact precaution; pet toxicology unresolved | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-4 | Other animals | Species-specific | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-5 | Plants & habitat | Species-specific | F-sarcobatus | No quantitative safe exposure established here. |
| black-greasewood-6 | Management & timing | Management synthesis | A-greasewood, F-sarcobatus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md
---
{
"id": "black-henbane",
"name": "Black henbane",
"scientific": "Hyoscyamus niger",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Highly poisonous; keep animals away",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-hyoscyamus-niger",
"S27",
"Fremont-list-definitions"
],
"description": "Black henbane: Highly poisonous; keep animals away. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-hyoscyamus-niger"
],
"scope": "Species-specific",
"note": "",
"id": "black-henbane-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-hyoscyamus-niger"
],
"scope": "Species-specific",
"note": "",
"id": "black-henbane-2"
},
{
"label": "People",
"sources": [
"N-hyoscyamus-niger"
],
"scope": "Species-specific",
"note": "",
"id": "black-henbane-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-hyoscyamus-niger"
],
"scope": "Species-specific",
"note": "",
"id": "black-henbane-4"
},
{
"label": "Other animals",
"sources": [
"N-hyoscyamus-niger"
],
"scope": "Species-specific",
"note": "",
"id": "black-henbane-5"
},
{
"id": "black-henbane-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/black-henbane.md"
}
---
# Black henbane
*Hyoscyamus niger*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Highly poisonous; keep animals away.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Pale yellow henbane flowers with purple veins and dark purple throats above lobed leaves.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Hyoscyamus_niger_0002.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/44/Hyoscyamus_niger_0002.JPG). Source-identified photograph with visual consistency check Hyoscyamus niger , Solanaceae, Henbane, Stinking Nightshade, flowers; Botanical Garden KIT, Karlsruhe, Germany. The whole, fresh, blooming plant is used in homeopathy as remedy: Hyoscyamus (Hyos.) Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem hairs** — Macro view of glandular hairs projecting from a green stem, with a 3 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Hyoscyamus_niger_sl42.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a9/Hyoscyamus_niger_sl42.jpg). Source-identified photograph with visual consistency check Stem with glandular hairs Taxonym: Hyoscyamus niger ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: S Hollabrunn, district Hollabrunn, Lower Austria - ca. 220 m a.s.l. Habitat: pumpkin field Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Whole flowering henbane plants with lobed leaves on disturbed gravelly ground.
Photo: Bjoertvedt; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Hyoscyamus_niger_IMG_8882_bulmeurt_hoved%C3%B6ya.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a9/Hyoscyamus_niger_IMG_8882_bulmeurt_hoved%C3%B6ya.JPG). Source-identified photograph with visual consistency check Photo of Hyoscyamus niger (norwegian: bulmeurt) at the island og Hovedøya, in the inner Oslofjord, Norway. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A coarse, hairy annual or biennial with sticky-looking leaves and yellowish flowers marked by purple veins. [N-hyoscyamus-niger](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/)
## Plants & habitat
Self-seeding produces persistent infestations on disturbed ground. Prevent mature fruits from scattering seed. [N-hyoscyamus-niger](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/)
## People
Tropane alkaloids can cause severe poisoning, including convulsions and coma. Do not taste or use it as a home remedy. [N-hyoscyamus-niger](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/)
## Dogs & cats
NC State flags dogs and cats. Treat suspected ingestion as urgent and contact a veterinarian. [N-hyoscyamus-niger](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/)
## Other animals
The source reports particular seed toxicity to pigs and flags horses. Animal avoidance is not a guarantee against poisoning. [N-hyoscyamus-niger](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-hyoscyamus-niger** — [hyoscyamus niger — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=black-henbane) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| black-henbane-1 | Recognize | Species-specific | N-hyoscyamus-niger | No quantitative safe exposure established here. |
| black-henbane-2 | Plants & habitat | Species-specific | N-hyoscyamus-niger | No quantitative safe exposure established here. |
| black-henbane-3 | People | Species-specific | N-hyoscyamus-niger | No quantitative safe exposure established here. |
| black-henbane-4 | Dogs & cats | Species-specific | N-hyoscyamus-niger | No quantitative safe exposure established here. |
| black-henbane-5 | Other animals | Species-specific | N-hyoscyamus-niger | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/index.md
---
{
"id": "blanketflower",
"name": "Blanketflower",
"scientific": "Gaillardia aristata",
"category": "xeriscape",
"status": "Colorado native; low-water garden plant",
"status_sources": [
"C-perennials"
],
"warning": "Contact dermatitis possible",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Many nursery blanketflowers are Gaillardia × grandiflora hybrids. Their appearance does not prove they are G. aristata.",
"source_ids": [
"C-perennials",
"N-gaillardia-aristata"
],
"description": "Blanketflower: Contact dermatitis possible. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-gaillardia-aristata"
],
"scope": "Species-specific",
"note": "",
"id": "blanketflower-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-gaillardia-aristata"
],
"scope": "Species-specific traits; garden judgment",
"note": "",
"id": "blanketflower-2"
},
{
"label": "People",
"sources": [
"N-gaillardia-aristata"
],
"scope": "Species-specific",
"note": "",
"id": "blanketflower-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "blanketflower-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "This review did not establish livestock toxicity despite documented wildlife use.",
"id": "blanketflower-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"blanketflower-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"blanketflower-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/blanketflower.md"
}
---
# Blanketflower
*Gaillardia aristata*
**Colorado native; low-water garden plant.** [C-perennials](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/)
> **Contact dermatitis possible.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Many nursery blanketflowers are Gaillardia × grandiflora hybrids. Their appearance does not prove they are G. aristata.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Open yellow-rayed blanketflower heads with orange-yellow central disks and a reddish inner ring.
Photo: NPS / Jacob W. Frank; [Public domain](https://commons.wikimedia.org/wiki/File:Blanketflower_-_Gaillardia_aristata_(23515821570).jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Blanketflower_-_Gaillardia_aristata_(23515821570).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/39/Blanketflower_-_Gaillardia_aristata_%2823515821570%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaves and developing heads** — Hairy narrow leaves, upright stems, and developing flower heads viewed from below.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Gaillardia_aristata_-_blanketflower_-_52378800238.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0f/Gaillardia_aristata_-_blanketflower_-_52378800238.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf and stem** — Close side view of an alternate elongated leaf and stem, both covered in coarse hairs.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Gaillardia_aristata_(3750286513).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c1/Gaillardia_aristata_%283750286513%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Daisy-like heads with yellow or reddish ray flowers and darker centers; leaves and stems have hairs. [N-gaillardia-aristata](https://plants.ces.ncsu.edu/plants/gaillardia-aristata/)
## Plants & habitat
Suited to hot, dry sites with drainage; seed and division propagate it. Flowers support pollinators and seedheads attract birds. Garden judgment: remove unwanted volunteers around smaller plants. [N-gaillardia-aristata](https://plants.ces.ncsu.edu/plants/gaillardia-aristata/)
## People
Contact dermatitis is reported; wear gloves if sensitive when handling plants. [N-gaillardia-aristata](https://plants.ces.ncsu.edu/plants/gaillardia-aristata/)
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
This review did not establish livestock toxicity despite documented wildlife use. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-perennials** — [Native Herbaceous Perennials for Colorado Landscapes](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/), Colorado State University Extension. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
- **N-gaillardia-aristata** — [Gaillardia aristata — Plant Toolbox](https://plants.ces.ncsu.edu/plants/gaillardia-aristata/), NC State Extension. Accessed 2026-09-07T00:23:59+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=blanketflower) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Many nursery blanketflowers are Gaillardia × grandiflora hybrids. Their appearance does not prove they are G. aristata.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| blanketflower-1 | Recognize | Species-specific | N-gaillardia-aristata | No quantitative exposure threshold established here. |
| blanketflower-2 | Plants & habitat | Species-specific traits; garden judgment | N-gaillardia-aristata | No quantitative exposure threshold established here. |
| blanketflower-3 | People | Species-specific | N-gaillardia-aristata | No quantitative exposure threshold established here. |
| blanketflower-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| blanketflower-5 | Other animals | Review limitation | Review limitation | This review did not establish livestock toxicity despite documented wildlife use. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md
---
{
"id": "bohemian-knotweed",
"name": "Bohemian knotweed",
"scientific": "Reynoutria × bohemica",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Hybrid regrows from small fragments",
"warning_tone": "caution",
"aliases": [
"Fallopia x bohemicum",
"Fallopia × bohemica",
"Polygonum x bohemicum"
],
"taxonomy_note": "This is the Japanese × giant knotweed hybrid. Intermediate-looking leaves alone cannot establish a hybrid identification.",
"source_ids": [
"CO-rules-2025",
"WA-bohemian-knotweed",
"S27",
"Fremont-list-definitions"
],
"description": "Bohemian knotweed: Hybrid regrows from small fragments. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-bohemian-knotweed"
],
"scope": "Species-specific",
"note": "",
"id": "bohemian-knotweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-bohemian-knotweed"
],
"scope": "Species-specific",
"note": "",
"id": "bohemian-knotweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bohemian-knotweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bohemian-knotweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bohemian-knotweed-5"
},
{
"id": "bohemian-knotweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"bohemian-knotweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"bohemian-knotweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"bohemian-knotweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/bohemian-knotweed.md"
}
---
# Bohemian knotweed
*Reynoutria × bohemica*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Hybrid regrows from small fragments.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is the Japanese × giant knotweed hybrid. Intermediate-looking leaves alone cannot establish a hybrid identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**young foliage** — Young rounded leaves with reddish-purple tones and a folded emerging leaf.
Photo: Patrick Hacker; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/158864261); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/274484098/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid, not a substituted parent species. The selected observation is research grade; these views show young foliage and leaf hairs, and are not a genetic or specimen-based confirmation of hybridity. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf hairs** — Magnified view of a leaf edge and vein with short projecting hairs.
Photo: Patrick Hacker; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/158864261); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/274484178/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid, not a substituted parent species. The selected observation is research grade; these views show young foliage and leaf hairs, and are not a genetic or specimen-based confirmation of hybridity. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**young growth** — A small young knotweed shoot with purplish leaves in mixed low vegetation.
Photo: Patrick Hacker; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/158864261); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/274484247/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid, not a substituted parent species. The selected observation is research grade; these views show young foliage and leaf hairs, and are not a genetic or specimen-based confirmation of hybridity. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A spreading perennial with hollow stems and leaves intermediate between Japanese and giant knotweed. Leaf-base shape and underside hairs help identification. [WA-bohemian-knotweed](https://www.nwcb.wa.gov/weeds/bohemian-knotweed)
## Plants & habitat
Rhizomes, stem fragments and seed spread persistent colonies that exclude other streambank plants. [WA-bohemian-knotweed](https://www.nwcb.wa.gov/weeds/bohemian-knotweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-bohemian-knotweed** — [Bohemian Knotweed](https://www.nwcb.wa.gov/weeds/bohemian-knotweed), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:00+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=bohemian-knotweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is the Japanese × giant knotweed hybrid. Intermediate-looking leaves alone cannot establish a hybrid identification.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| bohemian-knotweed-1 | Recognize | Species-specific | WA-bohemian-knotweed | No quantitative safe exposure established here. |
| bohemian-knotweed-2 | Plants & habitat | Species-specific | WA-bohemian-knotweed | No quantitative safe exposure established here. |
| bohemian-knotweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| bohemian-knotweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| bohemian-knotweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/index.md
---
{
"id": "bouncingbet",
"name": "Bouncingbet",
"scientific": "Saponaria officinalis",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Saponins can cause digestive poisoning",
"warning_tone": "caution",
"aliases": [
"soapwort",
"bouncing bet"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-saponaria-officinalis",
"S27",
"Fremont-list-definitions"
],
"description": "Bouncingbet: Saponins can cause digestive poisoning. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-saponaria-officinalis"
],
"scope": "Species-specific",
"note": "",
"id": "bouncingbet-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-saponaria-officinalis"
],
"scope": "Species-specific",
"note": "",
"id": "bouncingbet-2"
},
{
"label": "People",
"sources": [
"N-saponaria-officinalis"
],
"scope": "Species-specific",
"note": "",
"id": "bouncingbet-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bouncingbet-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bouncingbet-5"
},
{
"id": "bouncingbet-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"bouncingbet-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"bouncingbet-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/bouncingbet.md"
}
---
# Bouncingbet
*Saponaria officinalis*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Saponins can cause digestive poisoning.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright soapwort stem with opposite leaves and a pale flower cluster in sandy ground.
Photo: Ryan Hodnett; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Common_Soapwort_(Saponaria_officinalis)_-_Bayfield,_Ontario.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7a/Common_Soapwort_%28Saponaria_officinalis%29_-_Bayfield%2C_Ontario.jpg). Source-identified photograph with visual consistency check Common Soapwort ( Saponaria officinalis ) in Bayfield, Ontario, Canada. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Pale five-petaled soapwort flowers with elongated tubular calyces on an upright flowering stem.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Saponaria_officinalis_sl11.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/64/Saponaria_officinalis_sl11.jpg). Source-identified photograph with visual consistency check Inflorescence Taxonym: Saponaria officinalis ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Donauinsel next to Schwarzlackenau, Vienna-Floridsdorf - ca. 160 m a.s.l. Habitat: wayside Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**young foliage** — A patch of young soapwort shoots with paired broad green leaves emerging from bare soil.
Photo: 4028mdk09; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Saponaria_officinalis_April_2012.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/3/36/Saponaria_officinalis_April_2012.JPG). Source-identified photograph with visual consistency check Gewöhnliches Seifenkraut (Saponaria officinalis), fotografiert in Südhessen (Deutschland) Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An upright perennial with opposite, prominently veined leaves and pink or white flowers with five notched petals. [N-saponaria-officinalis](https://plants.ces.ncsu.edu/plants/saponaria-officinalis/)
## Plants & habitat
An introduced garden escape occurring along roads and disturbed places. Historical soap use does not establish ingestion safety. [N-saponaria-officinalis](https://plants.ces.ncsu.edu/plants/saponaria-officinalis/)
## People
Saponic glycosides in roots and seeds can cause nausea, vomiting and diarrhea. [N-saponaria-officinalis](https://plants.ces.ncsu.edu/plants/saponaria-officinalis/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-saponaria-officinalis** — [saponaria officinalis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/saponaria-officinalis/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=bouncingbet) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| bouncingbet-1 | Recognize | Species-specific | N-saponaria-officinalis | No quantitative safe exposure established here. |
| bouncingbet-2 | Plants & habitat | Species-specific | N-saponaria-officinalis | No quantitative safe exposure established here. |
| bouncingbet-3 | People | Species-specific | N-saponaria-officinalis | No quantitative safe exposure established here. |
| bouncingbet-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| bouncingbet-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md
---
{
"id": "broom-snakeweed",
"name": "Broom snakeweed",
"scientific": "Gutierrezia sarothrae",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Livestock poisoning and abortion risk when heavily eaten",
"warning_tone": "danger",
"aliases": [
"broomweed",
"snakeweed"
],
"taxonomy_note": "Distinct from threadleaf snakeweed (Gutierrezia microcephala) and annual broomweeds. Toxicity varies; published livestock findings do not provide pet exposure limits.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-gutierrezia",
"S27"
],
"description": "Broom snakeweed: Livestock poisoning and abortion risk when heavily eaten. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-gutierrezia"
],
"scope": "Species-specific",
"note": "",
"id": "broom-snakeweed-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "broom-snakeweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "broom-snakeweed-3"
},
{
"label": "Other animals",
"sources": [
"F-gutierrezia"
],
"scope": "Species-specific",
"note": "",
"id": "broom-snakeweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-gutierrezia"
],
"scope": "Species-specific",
"note": "",
"id": "broom-snakeweed-5"
},
{
"label": "Management & timing",
"sources": [
"F-gutierrezia"
],
"scope": "Management synthesis",
"note": "",
"id": "broom-snakeweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"broom-snakeweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"broom-snakeweed-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 56; Gutierrezia sarothrae",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Gutierrezia sarothrae"
},
"source": "content/plants/broom-snakeweed.md"
}
---
# Broom snakeweed
*Gutierrezia sarothrae*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Livestock poisoning and abortion risk when heavily eaten.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinct from threadleaf snakeweed (Gutierrezia microcephala) and annual broomweeds. Toxicity varies; published livestock findings do not provide pet exposure limits.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Small branching broom snakeweed plant with yellow flower clusters above a woody base on rocky ground.
Photo: CK2AZ; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/15725119); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/23477453/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers** — Yellow broom snakeweed flower heads held against a hand, showing the small rays and central florets.
Photo: Amy; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/62535662); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/100211579/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves-stem** — Slender green broom snakeweed stem and narrow leaves held against a hand.
Photo: W. Terry Hunefeld; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/8523021); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/11379388/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A low, bushy perennial with many fine upright branches arising from a woody base and small yellow flower heads. It is common in dry, open western habitats. [F-gutierrezia](https://research.fs.usda.gov/feis/species-reviews/gutsar)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Heavy consumption can cause livestock illness, death or abortion. Risk varies with growth stage, soil and available forage. This species can also accumulate selenium under suitable soil conditions. [F-gutierrezia](https://research.fs.usda.gov/feis/species-reviews/gutsar)
## Plants & habitat
Dense populations can be a rangeland problem, although the shrub is native and supplies food for some wildlife. Its presence alone is not a diagnosis of poor management. [F-gutierrezia](https://research.fs.usda.gov/feis/species-reviews/gutsar)
## Management & timing
Assess grazing pressure, forage availability and site condition with a range specialist before choosing control. Keep livestock from relying on a snakeweed-dominated patch for feed. [F-gutierrezia](https://research.fs.usda.gov/feis/species-reviews/gutsar)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-gutierrezia** — [Broom snakeweed](https://research.fs.usda.gov/feis/species-reviews/gutsar), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=broom-snakeweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 56; Gutierrezia sarothrae. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Distinct from threadleaf snakeweed (Gutierrezia microcephala) and annual broomweeds. Toxicity varies; published livestock findings do not provide pet exposure limits.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| broom-snakeweed-1 | Identification | Species-specific | F-gutierrezia | No quantitative safe exposure established here. |
| broom-snakeweed-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| broom-snakeweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| broom-snakeweed-4 | Other animals | Species-specific | F-gutierrezia | No quantitative safe exposure established here. |
| broom-snakeweed-5 | Plants & habitat | Species-specific | F-gutierrezia | No quantitative safe exposure established here. |
| broom-snakeweed-6 | Management & timing | Management synthesis | F-gutierrezia | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md
---
{
"id": "buffalobur",
"name": "Buffalobur",
"scientific": "Solanum rostratum",
"category": "native",
"status": "Great Plains native; documented in Colorado",
"status_sources": [
"I-buffalobur",
"U-buffalobur"
],
"warning": "Sharp spines; toxic to livestock",
"warning_tone": "caution",
"aliases": [
"buffalo-bur",
"Colorado bur"
],
"taxonomy_note": "Washington lists this plant as a noxious weed in that state. That legal designation is not transferred to Colorado.",
"source_ids": [
"I-buffalobur",
"U-buffalobur",
"W-buffalobur"
],
"description": "Buffalobur: Sharp spines; toxic to livestock. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"I-buffalobur"
],
"scope": "Species-specific",
"note": "",
"id": "buffalobur-1"
},
{
"label": "Plants & habitat",
"sources": [
"W-buffalobur"
],
"scope": "Species-specific",
"note": "",
"id": "buffalobur-2"
},
{
"label": "People",
"sources": [
"I-buffalobur"
],
"scope": "Documented spines; editorial risk inference",
"note": "",
"id": "buffalobur-3"
},
{
"label": "Dogs & cats",
"sources": [
"W-buffalobur"
],
"scope": "Physical-risk inference; pet evidence gap",
"note": "",
"id": "buffalobur-4"
},
{
"label": "Other animals",
"sources": [
"W-buffalobur"
],
"scope": "Species-specific",
"note": "",
"id": "buffalobur-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"buffalobur-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"buffalobur-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/buffalobur.md"
}
---
# Buffalobur
*Solanum rostratum*
**Great Plains native; documented in Colorado.** [I-buffalobur](https://crops.extension.iastate.edu/encyclopedia/buffalobur) [U-buffalobur](https://botany-server3.colorado.edu/collections/list.php?page=3&taxa=2365&taxontype=2&usethes=1)
> **Sharp spines; toxic to livestock.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Washington lists this plant as a noxious weed in that state. That legal designation is not transferred to Colorado.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**leaves and prickles** — Deeply lobed leaves and prickly stems, with a yellow flower visible at the edge.
Photo: Juan Carlos Fonseca Mata; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Ayohuiztle_(Solanum_rostratum),_hoja.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/59/Ayohuiztle_%28Solanum_rostratum%29%2C_hoja.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Side view of a yellow buffalo-bur flower showing unequal stamens, hairy buds, and conspicuous prickles.
Photo: Dcrjsr; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Buffalo_berry_Solanum_rostratum_flower_close.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/55/Buffalo_berry_Solanum_rostratum_flower_close.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**whole plant** — A spreading buffalo-bur plant in rocky soil, with lobed leaves, yellow flowers, and spiny fruiting structures.
Photo: Dcrjsr; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Buffalo_berry_Solanum_rostratum_plant.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d0/Buffalo_berry_Solanum_rostratum_plant.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow, five-lobed flowers; deeply lobed leaves with conspicuous spines on the veins and stems. This is an annual. [I-buffalobur](https://crops.extension.iastate.edu/encyclopedia/buffalobur)
## Plants & habitat
Can compete strongly with forage in disturbed pastures. Prevent seed production where removal is needed. [W-buffalobur](https://www.nwcb.wa.gov/weeds/buffalobur)
## People
The abundant spines present a puncture hazard. Use sturdy gloves for removal; this is a physical-risk inference from the documented spines. Human ingestion effects are not established here. [I-buffalobur](https://crops.extension.iastate.edu/encyclopedia/buffalobur)
*Evidence scope: Documented spines; editorial risk inference.*
## Dogs & cats
Spines may injure paws or mouths. Pet-specific chemical toxicity is not established by the livestock source; prevent chewing. [W-buffalobur](https://www.nwcb.wa.gov/weeds/buffalobur)
*Evidence scope: Physical-risk inference; pet evidence gap.*
## Other animals
Reported toxic to livestock; burs also catch in sheep wool. [W-buffalobur](https://www.nwcb.wa.gov/weeds/buffalobur)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **I-buffalobur** — [Buffalobur](https://crops.extension.iastate.edu/encyclopedia/buffalobur), Iowa State University Extension. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
- **U-buffalobur** — [Solanum rostratum herbarium collection records](https://botany-server3.colorado.edu/collections/list.php?page=3&taxa=2365&taxontype=2&usethes=1), University of Colorado Museum of Natural History. Accessed 2026-09-07. Locator: COLO:V specimens 00785139 and 00785204; Colorado localities.
- **W-buffalobur** — [Buffalobur](https://www.nwcb.wa.gov/weeds/buffalobur), Washington State Noxious Weed Control Board. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=buffalobur) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Washington lists this plant as a noxious weed in that state. That legal designation is not transferred to Colorado.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| buffalobur-1 | Recognize | Species-specific | I-buffalobur | No quantitative exposure threshold established here. |
| buffalobur-2 | Plants & habitat | Species-specific | W-buffalobur | No quantitative exposure threshold established here. |
| buffalobur-3 | People | Documented spines; editorial risk inference | I-buffalobur | No quantitative exposure threshold established here. |
| buffalobur-4 | Dogs & cats | Physical-risk inference; pet evidence gap | W-buffalobur | No quantitative exposure threshold established here. |
| buffalobur-5 | Other animals | Species-specific | W-buffalobur | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/index.md
---
{
"id": "bulbous-bluegrass",
"name": "Bulbous bluegrass",
"scientific": "Poa bulbosa",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Early-season grass spreads by bulbils",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "The USU page has an unrelated heading, but its scientific-name field and grass description identify Poa bulbosa. Only that species-specific body is used.",
"source_ids": [
"CO-rules-2025",
"U-bulbous",
"S27",
"Fremont-list-definitions"
],
"description": "Bulbous bluegrass: Early-season grass spreads by bulbils. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"U-bulbous"
],
"scope": "Species-specific",
"note": "",
"id": "bulbous-bluegrass-1"
},
{
"label": "Plants & habitat",
"sources": [
"U-bulbous"
],
"scope": "Species-specific",
"note": "",
"id": "bulbous-bluegrass-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bulbous-bluegrass-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bulbous-bluegrass-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "bulbous-bluegrass-5"
},
{
"id": "bulbous-bluegrass-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"bulbous-bluegrass-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"bulbous-bluegrass-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"bulbous-bluegrass-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/bulbous-bluegrass.md"
}
---
# Bulbous bluegrass
*Poa bulbosa*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Early-season grass spreads by bulbils.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The USU page has an unrelated heading, but its scientific-name field and grass description identify Poa bulbosa. Only that species-specific body is used.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Low grass clump with slender upright culms and compact dark-tipped panicles.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Poa_bulbosa_sl3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/08/Poa_bulbosa_sl3.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**basal-bulbs** — Close view of swollen pale bulb-like shoot bases above a fibrous root cluster.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Poa_bulbosa_sl6.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/db/Poa_bulbosa_sl6.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**bulbil** — A single leafy bulbil photographed with a millimeter scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Poa_bulbosa_sl8.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8c/Poa_bulbosa_sl8.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Bulbiferous or viviparous forms are included. A bulbil-producing panicle and swollen shoot bases are different structures; photograph captions distinguish them. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A small cool-season perennial with swollen stem bases and purple-green bulbils replacing many flowers in the seedhead. [U-bulbous](https://extension.usu.edu/rangeplants/grasses-and-grasslikes/bulbous-bluegrass)
## Plants & habitat
Grows early and becomes dormant as soils dry. It favors disturbed sites; the source does not describe it as equally aggressive in vigorous native vegetation. [U-bulbous](https://extension.usu.edu/rangeplants/grasses-and-grasslikes/bulbous-bluegrass)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **U-bulbous** — [Bulbous bluegrass](https://extension.usu.edu/rangeplants/grasses-and-grasslikes/bulbous-bluegrass), Utah State University Extension. Accessed 2026-09-07T01:16:17+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=bulbous-bluegrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The USU page has an unrelated heading, but its scientific-name field and grass description identify Poa bulbosa. Only that species-specific body is used.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| bulbous-bluegrass-1 | Recognize | Species-specific | U-bulbous | No quantitative safe exposure established here. |
| bulbous-bluegrass-2 | Plants & habitat | Species-specific | U-bulbous | No quantitative safe exposure established here. |
| bulbous-bluegrass-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| bulbous-bluegrass-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| bulbous-bluegrass-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/index.md
---
{
"id": "bull-thistle",
"name": "Bull thistle",
"scientific": "Cirsium vulgare",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-bull-thistle"
],
"warning": "Sharp spines; competes with vegetation",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.",
"source_ids": [
"J-bull-thistle",
"Fremont-list-definitions"
],
"description": "Bull thistle: Sharp spines; competes with vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-bull-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "bull-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-bull-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "bull-thistle-2"
},
{
"label": "People",
"sources": [
"J-bull-thistle"
],
"scope": "Physical-risk inference from documented spines",
"note": "",
"id": "bull-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-bull-thistle"
],
"scope": "Physical-risk inference; toxicology gap",
"note": "",
"id": "bull-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed control source does not establish species-specific livestock chemical toxicity.",
"id": "bull-thistle-5"
},
{
"id": "bull-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"bull-thistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"bull-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/bull-thistle.md"
}
---
# Bull thistle
*Cirsium vulgare*
**Colorado noxious weed · List B — Stop the spread.** [J-bull-thistle](https://www.jeffco.us/2618/Bull-Thistle)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; competes with vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**seed-head** — White wind-dispersal hairs spreading from mature dry seed heads.
Photo: Dominicus Johannes Bergsma; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Zaadpluizen_van_Cirsium_vulgare_in_mild_avondlicht._Locatie,_De_Famberhorst_02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b6/Zaadpluizen_van_Cirsium_vulgare_in_mild_avondlicht._Locatie%2C_De_Famberhorst_02.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Purple flower head above a densely spiny involucre, with additional buds below.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cirsium_vulgare_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/40/Cirsium_vulgare_RF.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Deeply divided, rigidly spine-tipped leaves on a prickly green stem.
Photo: Rl; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:2007_Cirsium_vulgare_leaves.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/07/2007_Cirsium_vulgare_leaves.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Purple flowerheads with strongly spiny bracts; prickly leaves and a taproot. It usually flowers after a first-year rosette. [J-bull-thistle](https://www.jeffco.us/2618/Bull-Thistle)
## Plants & habitat
An introduced biennial of disturbed sites. Remove the root and prevent seed set, then monitor for seedlings. [J-bull-thistle](https://www.jeffco.us/2618/Bull-Thistle)
## People
Spines can puncture skin. Sturdy gloves are a practical precaution when handling; confirm identification before removing a thistle. [J-bull-thistle](https://www.jeffco.us/2618/Bull-Thistle)
*Evidence scope: Physical-risk inference from documented spines.*
## Dogs & cats
Spiny material can injure paws or mouths. Species-specific chemical toxicity is unresolved in this review. [J-bull-thistle](https://www.jeffco.us/2618/Bull-Thistle)
*Evidence scope: Physical-risk inference; toxicology gap.*
## Other animals
The reviewed control source does not establish species-specific livestock chemical toxicity. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-bull-thistle** — [Bull Thistle](https://www.jeffco.us/2618/Bull-Thistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:21+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=bull-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| bull-thistle-1 | Recognize | Species-specific | J-bull-thistle | No quantitative exposure threshold established here. |
| bull-thistle-2 | Plants & habitat | Species-specific | J-bull-thistle | No quantitative exposure threshold established here. |
| bull-thistle-3 | People | Physical-risk inference from documented spines | J-bull-thistle | No quantitative exposure threshold established here. |
| bull-thistle-4 | Dogs & cats | Physical-risk inference; toxicology gap | J-bull-thistle | No quantitative exposure threshold established here. |
| bull-thistle-5 | Other animals | Review limitation | Review limitation | The reviewed control source does not establish species-specific livestock chemical toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/index.md
---
{
"id": "camelthorn",
"name": "Camelthorn",
"scientific": "Alhagi maurorum",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Thorns and deep spreading roots",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "The Washington legal class is not applied here; Colorado lists camelthorn on List A.",
"source_ids": [
"CO-rules-2025",
"WA-camelthorn",
"S27",
"Fremont-list-definitions"
],
"description": "Camelthorn: Thorns and deep spreading roots. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-camelthorn"
],
"scope": "Species-specific",
"note": "",
"id": "camelthorn-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-camelthorn"
],
"scope": "Species-specific",
"note": "",
"id": "camelthorn-2"
},
{
"label": "People",
"sources": [
"WA-camelthorn"
],
"scope": "Species-specific",
"note": "",
"id": "camelthorn-3"
},
{
"label": "Dogs & cats",
"sources": [
"WA-camelthorn"
],
"scope": "Species-specific",
"note": "",
"id": "camelthorn-4"
},
{
"label": "Other animals",
"sources": [
"WA-camelthorn"
],
"scope": "Species-specific",
"note": "",
"id": "camelthorn-5"
},
{
"id": "camelthorn-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"camelthorn-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/camelthorn.md"
}
---
# Camelthorn
*Alhagi maurorum*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Thorns and deep spreading roots.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The Washington legal class is not applied here; Colorado lists camelthorn on List A.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A dense, twiggy stand growing beside a paved edge.
Photo: Jesse Rorabaugh; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/88194613); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/145485558/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering branches** — Slender green branches bearing small pink-red pea-shaped flowers.
Photo: Jesse Rorabaugh; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/88194613); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/145485645/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**thorns and flowers** — A closer view of thorny branching stems, small leaves, and pink flowers.
Photo: Jesse Rorabaugh; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/88194613); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/145485729/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A spine-covered, branching perennial shrub with small pink-purple pea flowers and narrow, constricted seed pods. [WA-camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn)
## Plants & habitat
Deep rhizomes spread into rangeland and irrigated sites, competing with preferred forage. Root fragments can regrow. [WA-camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn)
## People
Spine-tipped branches pose a puncture hazard. Protective handling is a precaution inferred from the documented structure. [WA-camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn)
## Dogs & cats
Thorns may injure mouths or paws. A pet-specific chemical-toxicity assessment is not available here. [WA-camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn)
## Other animals
The source reports injury to some animals and poor palatability. That does not establish safe feed use. [WA-camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-camelthorn** — [Camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:08:59+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=camelthorn) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The Washington legal class is not applied here; Colorado lists camelthorn on List A.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| camelthorn-1 | Recognize | Species-specific | WA-camelthorn | No quantitative safe exposure established here. |
| camelthorn-2 | Plants & habitat | Species-specific | WA-camelthorn | No quantitative safe exposure established here. |
| camelthorn-3 | People | Species-specific | WA-camelthorn | No quantitative safe exposure established here. |
| camelthorn-4 | Dogs & cats | Species-specific | WA-camelthorn | No quantitative safe exposure established here. |
| camelthorn-5 | Other animals | Species-specific | WA-camelthorn | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/index.md
---
{
"id": "canada-goldenrod",
"name": "Canada goldenrod",
"scientific": "Solidago canadensis",
"category": "native",
"status": "Colorado native",
"status_sources": [
"N-solidago-canadensis"
],
"warning": "Spreads by roots and seed",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Goldenrod taxonomy is variable. Other Solidago species and plants sharing this common name require separate identification.",
"source_ids": [
"N-solidago-canadensis"
],
"description": "Canada goldenrod: Spreads by roots and seed. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-solidago-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "canada-goldenrod-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-solidago-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "canada-goldenrod-2"
},
{
"label": "People",
"sources": [
"N-solidago-canadensis"
],
"scope": "Reported distinction; safety limitation",
"note": "",
"id": "canada-goldenrod-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "canada-goldenrod-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific livestock ingestion safety was not established in this review.",
"id": "canada-goldenrod-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"canada-goldenrod-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"canada-goldenrod-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"canada-goldenrod-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/canada-goldenrod.md"
}
---
# Canada goldenrod
*Solidago canadensis*
**Colorado native.** [N-solidago-canadensis](https://plants.ces.ncsu.edu/plants/solidago-canadensis/)
> **Spreads by roots and seed.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Goldenrod taxonomy is variable. Other Solidago species and plants sharing this common name require separate identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flowering stem** — A goldenrod stem with a branching yellow flower plume and narrow, alternate toothed leaves.
Photo: Étienne Lacroix-Carignan; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/68713865); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/111333765/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. Identification follows the research-grade source; these photographs alone do not reliably exclude all similar Solidago taxa. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and habitat** — An upright goldenrod stand within mixed meadow vegetation; other plant species also occur in the frame.
Photo: Étienne Lacroix-Carignan; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/68713865); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/111333767/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. Identification follows the research-grade source; these photographs alone do not reliably exclude all similar Solidago taxa. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of individual small yellow flower heads along a branch; focus is strongest near the centre.
Photo: Étienne Lacroix-Carignan; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/68713865); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/111333782/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. Identification follows the research-grade source; these photographs alone do not reliably exclude all similar Solidago taxa. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Late-season, branching sprays of small yellow flowerheads on an upright perennial. [N-solidago-canadensis](https://plants.ces.ncsu.edu/plants/solidago-canadensis/)
## Plants & habitat
Spreads by seed and rhizomes; useful in meadow plantings but may need boundaries in small beds. Flowers attract pollinators and seeds feed birds. [N-solidago-canadensis](https://plants.ces.ncsu.edu/plants/solidago-canadensis/)
## People
Goldenrod is different from wind-pollinated ragweed. That distinction does not guarantee freedom from individual sensitivities or ingestion risk. [N-solidago-canadensis](https://plants.ces.ncsu.edu/plants/solidago-canadensis/)
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Species-specific livestock ingestion safety was not established in this review. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-solidago-canadensis** — [Solidago canadensis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/solidago-canadensis/), NC State Extension. Accessed 2026-09-07T00:23:58+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=canada-goldenrod) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Goldenrod taxonomy is variable. Other Solidago species and plants sharing this common name require separate identification.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| canada-goldenrod-1 | Recognize | Species-specific | N-solidago-canadensis | No quantitative exposure threshold established here. |
| canada-goldenrod-2 | Plants & habitat | Species-specific | N-solidago-canadensis | No quantitative exposure threshold established here. |
| canada-goldenrod-3 | People | Reported distinction; safety limitation | N-solidago-canadensis | No quantitative exposure threshold established here. |
| canada-goldenrod-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| canada-goldenrod-5 | Other animals | Review limitation | Review limitation | Species-specific livestock ingestion safety was not established in this review. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md
---
{
"id": "canada-thistle",
"name": "Canada thistle",
"scientific": "Cirsium arvense",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-canada-thistle"
],
"warning": "Sharp spines; competes with vegetation",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.",
"source_ids": [
"J-canada-thistle",
"Fremont-list-definitions"
],
"description": "Canada thistle: Sharp spines; competes with vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-canada-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "canada-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-canada-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "canada-thistle-2"
},
{
"label": "People",
"sources": [
"J-canada-thistle"
],
"scope": "Physical-risk inference from documented spines",
"note": "",
"id": "canada-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-canada-thistle"
],
"scope": "Physical-risk inference; toxicology gap",
"note": "",
"id": "canada-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed control source does not establish species-specific livestock chemical toxicity.",
"id": "canada-thistle-5"
},
{
"id": "canada-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"canada-thistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"canada-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/canada-thistle.md"
}
---
# Canada thistle
*Cirsium arvense*
**Colorado noxious weed · List B — Stop the spread.** [J-canada-thistle](https://www.jeffco.us/2616/Canada-Thistle)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; competes with vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flowering-stem** — Branching stem carrying numerous small pink-purple flower heads and buds.
Photo: Ivar Leidus; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Cirsium_arvense_-_p%C3%B5ldohakas.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/10/Cirsium_arvense_-_p%C3%B5ldohakas.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Close view of pale leaf underside with deeply lobed, sharply spiny margins.
Photo: Renée Kools; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cirsium_arvense_2025-07-23-8.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5a/Cirsium_arvense_2025-07-23-8.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seed-head** — White fluffy pappus spreading from mature thistle heads.
Photo: Ulaisaeva; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:%D0%A1%D0%B0%D0%BB%D1%82%D1%8B%D0%BA%D0%BE%D0%B2%D1%81%D0%BA%D0%B8%D0%B9_%D0%BB%D0%B5%D1%81%D0%BE%D0%BF%D0%B0%D1%80%D0%BA_20.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4f/%D0%A1%D0%B0%D0%BB%D1%82%D1%8B%D0%BA%D0%BE%D0%B2%D1%81%D0%BA%D0%B8%D0%B9_%D0%BB%D0%B5%D1%81%D0%BE%D0%BF%D0%B0%D1%80%D0%BA_20.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Clusters of relatively small purple flowerheads above spiny leaves on a root-spreading perennial. [J-canada-thistle](https://www.jeffco.us/2616/Canada-Thistle)
## Plants & habitat
Colonies spread through extensive roots and seed. One pull rarely removes the root system; sustained management is needed. [J-canada-thistle](https://www.jeffco.us/2616/Canada-Thistle)
## People
Spines can puncture skin. Sturdy gloves are a practical precaution when handling; confirm identification before removing a thistle. [J-canada-thistle](https://www.jeffco.us/2616/Canada-Thistle)
*Evidence scope: Physical-risk inference from documented spines.*
## Dogs & cats
Spiny material can injure paws or mouths. Species-specific chemical toxicity is unresolved in this review. [J-canada-thistle](https://www.jeffco.us/2616/Canada-Thistle)
*Evidence scope: Physical-risk inference; toxicology gap.*
## Other animals
The reviewed control source does not establish species-specific livestock chemical toxicity. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-canada-thistle** — [Canada Thistle](https://www.jeffco.us/2616/Canada-Thistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:21+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=canada-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| canada-thistle-1 | Recognize | Species-specific | J-canada-thistle | No quantitative exposure threshold established here. |
| canada-thistle-2 | Plants & habitat | Species-specific | J-canada-thistle | No quantitative exposure threshold established here. |
| canada-thistle-3 | People | Physical-risk inference from documented spines | J-canada-thistle | No quantitative exposure threshold established here. |
| canada-thistle-4 | Dogs & cats | Physical-risk inference; toxicology gap | J-canada-thistle | No quantitative exposure threshold established here. |
| canada-thistle-5 | Other animals | Review limitation | Review limitation | The reviewed control source does not establish species-specific livestock chemical toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md
---
{
"id": "catchweed-bedstraw",
"name": "Catchweed bedstraw",
"scientific": "Galium aparine",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Hooked hairs and burrs cling to fur and clothing",
"warning_tone": "caution",
"aliases": [
"cleavers",
"stickyweed",
"sticky willy"
],
"taxonomy_note": "Use Galium aparine for evidence matching. A common name such as goosegrass can also refer to unrelated grasses.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-galium-aparine",
"S27"
],
"description": "Catchweed bedstraw: Hooked hairs and burrs cling to fur and clothing. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-galium-aparine"
],
"scope": "Species-specific",
"note": "",
"id": "catchweed-bedstraw-1"
},
{
"label": "People",
"sources": [
"N-galium-aparine"
],
"scope": "Mechanical-contact precaution",
"note": "",
"id": "catchweed-bedstraw-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-galium-aparine"
],
"scope": "Mechanical-contact precaution; clinical evidence unresolved",
"note": "",
"id": "catchweed-bedstraw-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "catchweed-bedstraw-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-galium-aparine",
"C-floristic-2020"
],
"scope": "Species-specific",
"note": "",
"id": "catchweed-bedstraw-5"
},
{
"label": "Management & timing",
"sources": [
"N-galium-aparine"
],
"scope": "Species-specific",
"note": "",
"id": "catchweed-bedstraw-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"catchweed-bedstraw-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"catchweed-bedstraw-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 55; Galium aparine",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Galium aparine"
},
"source": "content/plants/catchweed-bedstraw.md"
}
---
# Catchweed bedstraw
*Galium aparine*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Hooked hairs and burrs cling to fur and clothing.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Use Galium aparine for evidence matching. A common name such as goosegrass can also refer to unrelated grasses.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers and young fruit** — Small white flowers and rounded young fruits at the tip of a prickly leafy shoot.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Galium_aparine_kz07.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/df/Galium_aparine_kz07.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Other bedstraws can have similar whorled leaves. The source identification is retained, with prickles and paired bristly fruits shown where visible. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf whorl** — A whorl of narrow leaves viewed from below, with small backward-pointing prickles along the margins.
Photo: Harry Rose from South West Rocks, Australia; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Galium_aparine_leaf3_(14432916838).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/ad/Galium_aparine_leaf3_%2814432916838%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Other bedstraws can have similar whorled leaves. The source identification is retained, with prickles and paired bristly fruits shown where visible. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**dry fruits** — Paired, bristly dry fruits remaining on a network of thin stems in winter.
Photo: Agnieszka Kwiecień, Nova; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Galium_aparine_Przytulia_czepna_2020-12-30_So%C5%82tysowice_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/18/Galium_aparine_Przytulia_czepna_2020-12-30_So%C5%82tysowice_01.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Other bedstraws can have similar whorled leaves. The source identification is retained, with prickles and paired bristly fruits shown where visible. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A weak-stemmed annual that climbs through other plants. Narrow leaves occur in whorls, typically six to eight; stems and fruits carry hooked hairs. Tiny flowers are pale and four-petaled. [N-galium-aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/)
## People
Scratchy stems and burrs catch on clothing and skin. Gloves are a practical handling precaution. [N-galium-aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/)
*Evidence scope: Mechanical-contact precaution.*
## Dogs & cats
Bristly fruits attach to fur. Check animals after moving through patches; the source does not establish pet ingestion toxicity or a frequency of injury. [N-galium-aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/)
*Evidence scope: Mechanical-contact precaution; clinical evidence unresolved.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It scrambles through vegetation in woods, floodplains and disturbed sites. CNHP treats it as native in Colorado; other sources discuss uncertainty over its broader origin. [N-galium-aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/) [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf)
## Management & timing
Pull young unwanted plants before flowering. Fragile stems can break and leave roots behind, so check for regrowth. [N-galium-aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-galium-aparine** — [Galium aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=catchweed-bedstraw) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 55; Galium aparine. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Use Galium aparine for evidence matching. A common name such as goosegrass can also refer to unrelated grasses.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| catchweed-bedstraw-1 | Identification | Species-specific | N-galium-aparine | No quantitative safe exposure established here. |
| catchweed-bedstraw-2 | People | Mechanical-contact precaution | N-galium-aparine | No quantitative safe exposure established here. |
| catchweed-bedstraw-3 | Dogs & cats | Mechanical-contact precaution; clinical evidence unresolved | N-galium-aparine | No quantitative safe exposure established here. |
| catchweed-bedstraw-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| catchweed-bedstraw-5 | Plants & habitat | Species-specific | N-galium-aparine, C-floristic-2020 | No quantitative safe exposure established here. |
| catchweed-bedstraw-6 | Management & timing | Species-specific | N-galium-aparine | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/catmint/index.md
---
{
"id": "catmint",
"name": "Catmint",
"scientific": "Nepeta × faassenii",
"category": "xeriscape",
"status": "Introduced garden hybrid",
"status_sources": [
"N-nepeta-x-faassenii"
],
"warning": "Spreading clumps; pet evidence gap",
"warning_tone": "caution",
"aliases": [
"blue catmint",
"Faassen catmint",
"Nepeta x faassenii"
],
"taxonomy_note": "Sterility is reported for this hybrid, not all plants sold as catmint. Verify cultivar and scientific name.",
"source_ids": [
"N-nepeta-x-faassenii"
],
"description": "Catmint: Spreading clumps; pet evidence gap. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-nepeta-x-faassenii"
],
"scope": "Species-specific",
"note": "",
"id": "catmint-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-nepeta-x-faassenii"
],
"scope": "Species-specific",
"note": "",
"id": "catmint-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "The horticultural source does not provide a human ingestion assessment.",
"id": "catmint-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-nepeta-x-faassenii"
],
"scope": "Species-specific attraction; toxicology gap",
"note": "",
"id": "catmint-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "catmint-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"catmint-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"catmint-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"catmint-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/catmint.md"
}
---
# Catmint
*Nepeta × faassenii*
**Introduced garden hybrid.** [N-nepeta-x-faassenii](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/)
> **Spreading clumps; pet evidence gap.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Sterility is reported for this hybrid, not all plants sold as catmint. Verify cultivar and scientific name.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Macro view of violet-blue, two-lipped flowers with darker spotting and hairy calyces.
Photo: Didier Descouens; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:(MHNT)_Nepeta_%C3%97_faassenii_-_flowers.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b9/%28MHNT%29_Nepeta_%C3%97_faassenii_-_flowers.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Opposite pairs of gray-green, toothed leaves viewed from above, with strongly textured surfaces.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Nepeta_faassenii_2019-08-11_3739.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1c/Nepeta_faassenii_2019-08-11_3739.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Low spreading clump in bare garden soil with numerous violet-blue flowering stems.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Nepeta_faassenii_2019-05-12_3090.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f8/Nepeta_faassenii_2019-05-12_3090.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Gray-green aromatic leaves, square stems and lavender-blue flowers. [N-nepeta-x-faassenii](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/)
## Plants & habitat
A drought-tolerant, sterile hybrid that expands as a clump; it is unlikely to reseed. Divide or trim when it outgrows its space. [N-nepeta-x-faassenii](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/)
## People
The horticultural source does not provide a human ingestion assessment. This is an evidence gap, not proof of safety.
## Dogs & cats
Its scent can attract cats. This does not establish ingestion safety. Catnip (Nepeta cataria) is a different taxon; its poison listing cannot automatically classify this hybrid. [N-nepeta-x-faassenii](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/)
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-nepeta-x-faassenii** — [Nepeta x faassenii — Plant Toolbox](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/), NC State Extension. Accessed 2026-09-07T00:23:58+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=catmint) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Sterility is reported for this hybrid, not all plants sold as catmint. Verify cultivar and scientific name.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| catmint-1 | Recognize | Species-specific | N-nepeta-x-faassenii | No quantitative exposure threshold established here. |
| catmint-2 | Plants & habitat | Species-specific | N-nepeta-x-faassenii | No quantitative exposure threshold established here. |
| catmint-3 | People | Review limitation | Review limitation | The horticultural source does not provide a human ingestion assessment. |
| catmint-4 | Dogs & cats | Species-specific attraction; toxicology gap | N-nepeta-x-faassenii | No quantitative exposure threshold established here. |
| catmint-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/catmint/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/catmint/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/catmint/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md
---
{
"id": "cheatgrass",
"name": "Cheatgrass / downy brome",
"scientific": "Bromus tectorum",
"category": "invasive",
"status": "Colorado List C — Manage widespread weeds",
"status_sources": [
"S20"
],
"warning": "Grass awns · Fire hazard",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S20",
"S22",
"S21",
"Fremont-list-definitions"
],
"description": "Cheatgrass / downy brome: Grass awns · Fire hazard. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S20"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "cheatgrass-1"
},
{
"label": "Plants & habitat",
"sources": [
"S20"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "cheatgrass-2"
},
{
"label": "People",
"sources": [
"S20"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "cheatgrass-3"
},
{
"label": "Dogs & cats",
"sources": [
"S22"
],
"scope": "General grass-awn guidance",
"note": "UC Davis discusses foxtails and other grass seed heads; it does not quantify Bromus tectorum-specific pet risk.",
"reviewed": "2026-09-06",
"id": "cheatgrass-4"
},
{
"label": "Other animals",
"sources": [
"S21",
"S20"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "cheatgrass-5"
},
{
"id": "cheatgrass-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/cheatgrass.md"
}
---
# Cheatgrass / downy brome
*Bromus tectorum*
**Colorado List C — Manage widespread weeds.** [S20](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Grass awns · Fire hazard.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**inflorescence** — Green to purple awned spikelets hang from slender drooping panicle branches.
Photo: AnRo0002; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:20160426Bromus_tectorum1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/13/20160426Bromus_tectorum1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other annual brome grasses can resemble cheatgrass. Photographs document source-identified B. tectorum; detailed spikelet and hair characters may be needed for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Short grass clump with narrow leaves and open drooping awned panicles.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Bromus_tectorum_kz01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/11/Bromus_tectorum_kz01.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other annual brome grasses can resemble cheatgrass. Photographs document source-identified B. tectorum; detailed spikelet and hair characters may be needed for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature-inflorescence** — Tawny mature awned spikelets hang in loose drooping clusters.
Photo: Michel Langeveld; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Bromus_tectorum_138999438.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/36/Bromus_tectorum_138999438.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other annual brome grasses can resemble cheatgrass. Photographs document source-identified B. tectorum; detailed spikelet and hair characters may be needed for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual grass with soft hairs and drooping seed heads. Often turns reddish-brown, then dries early in summer. [S20](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/)
## Plants & habitat
Competes early for resources, displaces native plants, and creates dry fuels that increase wildfire risk. [S20](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/)
## People
Dense, dry growth is highly flammable. The principal human hazard emphasized by the Colorado source is wildfire. [S20](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/)
## Dogs & cats
Barbed grass seeds can lodge in tissue and cause infection. Check fur and paws; seek veterinary help for persistent sneezing, head shaking, or an embedded seed. [S22](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails)
## Other animals
CSU lists cheatgrass among plants that cause mechanical injury to livestock. Habitat displacement also affects wildlife. [S21](https://cmg.extension.colostate.edu/wp-content/uploads/sites/42/2016/10/SourceUnitInRangeAndPastureMngmt_REVISED_5-22-2017.pdf) [S20](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S20** — [Cheatgrass and Wildfire](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/), Colorado State University Extension. Accessed 2026-09-07T00:23:55+00:00. Locator: Introduction; How to Identify Cheatgrass; Fire Hazards.
- **S22** — [Foxtails and Dogs](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails), UC Davis · School of Veterinary Medicine. Accessed 2026-09-06. Locator: Takeaways; signs; prevention.
- **S21** — [Source Unit in Range and Pasture Management](https://cmg.extension.colostate.edu/wp-content/uploads/sites/42/2016/10/SourceUnitInRangeAndPastureMngmt_REVISED_5-22-2017.pdf), Colorado State University Extension. Accessed 2026-09-07T00:23:55+00:00. Locator: Printed page 44: plants that can cause mechanical injury.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=cheatgrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| cheatgrass-1 | Recognize | Species-specific | S20 | No quantitative exposure threshold established here. |
| cheatgrass-2 | Plants & habitat | Species-specific | S20 | No quantitative exposure threshold established here. |
| cheatgrass-3 | People | Species-specific | S20 | No quantitative exposure threshold established here. |
| cheatgrass-4 | Dogs & cats | General grass-awn guidance | S22 | UC Davis discusses foxtails and other grass seed heads; it does not quantify Bromus tectorum-specific pet risk. |
| cheatgrass-5 | Other animals | Species-specific | S21, S20 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/chicory/index.md
---
{
"id": "chicory",
"name": "Chicory",
"scientific": "Cichorium intybus",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Roadside and pasture spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Cultivated chicories and roadside plants can share a species name. This guide does not assess food harvesting or roadside contamination.",
"source_ids": [
"CO-rules-2025",
"N-cichorium-intybus",
"S27",
"Fremont-list-definitions"
],
"description": "Chicory: Roadside and pasture spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-cichorium-intybus"
],
"scope": "Species-specific",
"note": "",
"id": "chicory-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-cichorium-intybus"
],
"scope": "Species-specific",
"note": "",
"id": "chicory-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "chicory-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "chicory-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "chicory-5"
},
{
"id": "chicory-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"chicory-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"chicory-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"chicory-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/chicory.md"
}
---
# Chicory
*Cichorium intybus*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Roadside and pasture spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Cultivated chicories and roadside plants can share a species name. This guide does not assess food harvesting or roadside contamination.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Tall branched flowering plant above broad lower leaves at a grassy field edge.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Cichorium_intybus_001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/43/Cichorium_intybus_001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage-flowers** — Blue flower heads among long green leaves and stiff branching stems.
Photo: 4028mdk09; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Pflanze_mit_blauen_Bl%C3%BCten.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/a/ab/Pflanze_mit_blauen_Bl%C3%BCten.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Pale blue strap-shaped florets form a single chicory flower head.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:CICHORIUM_INTYBUS_-_MORIPOL_-_IB-765_(Xicoria).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/8/86/CICHORIUM_INTYBUS_-_MORIPOL_-_IB-765_%28Xicoria%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Bright blue flowerheads grow along wiry stems above a basal leaf rosette; the plant has a deep taproot. [N-cichorium-intybus](https://plants.ces.ncsu.edu/plants/cichorium-intybus/)
## Plants & habitat
Naturalized in disturbed ground, fields and roadsides. The source describes less frequent invasion of intact natural habitats; this is not a top poisoning priority. [N-cichorium-intybus](https://plants.ces.ncsu.edu/plants/cichorium-intybus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-cichorium-intybus** — [cichorium intybus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/cichorium-intybus/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=chicory) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Cultivated chicories and roadside plants can share a species name. This guide does not assess food harvesting or roadside contamination.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| chicory-1 | Recognize | Species-specific | N-cichorium-intybus | No quantitative safe exposure established here. |
| chicory-2 | Plants & habitat | Species-specific | N-cichorium-intybus | No quantitative safe exposure established here. |
| chicory-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| chicory-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| chicory-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/chicory/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/chicory/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/chicory/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/index.md
---
{
"id": "chinese-clematis",
"name": "Chinese clematis",
"scientific": "Clematis orientalis",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Smothers vegetation; irritating plant compounds",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Native clematis can be difficult to distinguish when not flowering. The toxicology reference treats Clematis broadly; horticultural recommendations for other clematis are not applied to this listed weed.",
"source_ids": [
"CO-rules-2025",
"J-chinese-clematis",
"N-clematis",
"S27",
"Fremont-list-definitions"
],
"description": "Chinese clematis: Smothers vegetation; irritating plant compounds. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-chinese-clematis"
],
"scope": "Species-specific",
"note": "",
"id": "chinese-clematis-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-chinese-clematis"
],
"scope": "Species-specific",
"note": "",
"id": "chinese-clematis-2"
},
{
"label": "People",
"sources": [
"N-clematis"
],
"scope": "Genus-level warning, not a C. orientalis exposure series",
"note": "",
"id": "chinese-clematis-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-clematis"
],
"scope": "Genus-level warning",
"note": "",
"id": "chinese-clematis-4"
},
{
"label": "Other animals",
"sources": [
"N-clematis"
],
"scope": "Genus-level warning",
"note": "",
"id": "chinese-clematis-5"
},
{
"id": "chinese-clematis-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"chinese-clematis-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/chinese-clematis.md"
}
---
# Chinese clematis
*Clematis orientalis*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Smothers vegetation; irritating plant compounds.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Native clematis can be difficult to distinguish when not flowering. The toxicology reference treats Clematis broadly; horticultural recommendations for other clematis are not applied to this listed weed.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruits** — Several clematis fruit clusters with long, silky, twisting tails on woody stems.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Clematis_orientalis_kz01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b2/Clematis_orientalis_kz01.jpg). Source-identified photograph with visual consistency check Clematis orientalis in the Botanischer Garten, Berlin-Dahlem Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Yellow, nodding clematis flowers with spreading sepals and numerous stamens.
Photo: Yuriy75; [Public domain](https://commons.wikimedia.org/wiki/File:Clematis_orientalis;_Baikonur_03.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Clematis_orientalis;_Baikonur_03.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4b/Clematis_orientalis%3B_Baikonur_03.jpg). Source-identified photograph with visual consistency check Ломонос восточный ( Clematis orientalis ), цветки. Город Байконур, Казахстан Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**vine and foliage** — Dense green clematis foliage bearing many yellow flowers on a climbing or spreading vine.
Photo: Ruslan Kastani; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Clematis_orientalis_vine_flowering_in_Semey_Ormany.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b1/Clematis_orientalis_vine_flowering_in_Semey_Ormany.jpg). Source-identified photograph with visual consistency check State Forest Nature Reservat "Semey Ormany": East Kazakhstan Region Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A perennial vine with compound leaves, yellow bell-shaped flowers and feathery seedheads. [J-chinese-clematis](https://www.jeffco.us/2530/Chinese-Clematis)
## Plants & habitat
Climbs fences, shrubs and trees; heavy coverage can kill supporting vegetation. [J-chinese-clematis](https://www.jeffco.us/2530/Chinese-Clematis)
## People
NC State’s Clematis account reports mouth injury after ingestion and contact dermatitis. Use gloves and avoid tasting. [N-clematis](https://plants.ces.ncsu.edu/plants/clematis/)
*Evidence scope: Genus-level warning, not a C. orientalis exposure series.*
## Dogs & cats
The genus source flags dogs and cats for vomiting, drooling and diarrhea. Keep pets from chewing; species-specific thresholds are unresolved. [N-clematis](https://plants.ces.ncsu.edu/plants/clematis/)
*Evidence scope: Genus-level warning.*
## Other animals
The same genus source flags horses. No safe forage amount is established for Chinese clematis. [N-clematis](https://plants.ces.ncsu.edu/plants/clematis/)
*Evidence scope: Genus-level warning.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-chinese-clematis** — [Chinese Clematis](https://www.jeffco.us/2530/Chinese-Clematis), Jefferson County, Colorado. Accessed 2026-09-07T01:08:55+00:00. Locator: Species description and management.
- **N-clematis** — [Clematis](https://plants.ces.ncsu.edu/plants/clematis/), NC State Extension. Accessed 2026-09-07T01:16:20+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=chinese-clematis) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Native clematis can be difficult to distinguish when not flowering. The toxicology reference treats Clematis broadly; horticultural recommendations for other clematis are not applied to this listed weed.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| chinese-clematis-1 | Recognize | Species-specific | J-chinese-clematis | No quantitative safe exposure established here. |
| chinese-clematis-2 | Plants & habitat | Species-specific | J-chinese-clematis | No quantitative safe exposure established here. |
| chinese-clematis-3 | People | Genus-level warning, not a C. orientalis exposure series | N-clematis | No quantitative safe exposure established here. |
| chinese-clematis-4 | Dogs & cats | Genus-level warning | N-clematis | No quantitative safe exposure established here. |
| chinese-clematis-5 | Other animals | Genus-level warning | N-clematis | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/index.md
---
{
"id": "common-blue-violet",
"name": "Common blue violet",
"scientific": "Viola sororia",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A native volunteer; identify the species before removing",
"warning_tone": "caution",
"aliases": [
"wild violet",
"blue violet"
],
"taxonomy_note": "This is one member of CSU’s broader “Viola spp.” topic, not coverage of every Colorado violet. CNHP includes Viola sororia as native; photos and the profile do not resolve all members of the species complex.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-viola-sororia",
"C-descriptions",
"S27"
],
"description": "Common blue violet: A native volunteer; identify the species before removing. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-viola-sororia"
],
"scope": "Species-specific",
"note": "",
"id": "common-blue-violet-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-blue-violet-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-blue-violet-3"
},
{
"label": "Other animals",
"sources": [
"N-viola-sororia"
],
"scope": "Species-specific",
"note": "",
"id": "common-blue-violet-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-viola-sororia"
],
"scope": "Species-specific",
"note": "",
"id": "common-blue-violet-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions"
],
"scope": "Viola group management",
"note": "",
"id": "common-blue-violet-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-blue-violet-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-blue-violet-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-blue-violet-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 85; Viola sororia",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Viola sororia"
},
"source": "content/plants/common-blue-violet.md"
}
---
# Common blue violet
*Viola sororia*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A native volunteer; identify the species before removing.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is one member of CSU’s broader “Viola spp.” topic, not coverage of every Colorado violet. CNHP includes Viola sororia as native; photos and the profile do not resolve all members of the species complex.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — A single violet flower with purple-and-pale petals and darker veins leading toward its center.
Photo: James Steakley; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Viola_sororia_color_variation.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4d/Viola_sororia_color_variation.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified V. sororia, a variable violet with differing flower colors and taxonomic treatments. Similar stemless violets and hybrids require additional characters; no cultivar, segregate taxon, or hybrid status is determined from these photographs. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf** — Broad heart-shaped green leaves with toothed edges and radiating veins.
Photo: Dalgial; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Viola_sororia_4.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bd/Viola_sororia_4.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified V. sororia, a variable violet with differing flower colors and taxonomic treatments. Similar stemless violets and hybrids require additional characters; no cultivar, segregate taxon, or hybrid status is determined from these photographs. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit-flower** — A low patch of purple-flowered violets with broad heart-shaped leaves among ground vegetation.
Photo: Famartin; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:2016-04-16_13_18_40_Violets_blooming_along_the_West_Branch_Shabakunk_Creek_in_Ewing,_New_Jersey.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f3/2016-04-16_13_18_40_Violets_blooming_along_the_West_Branch_Shabakunk_Creek_in_Ewing%2C_New_Jersey.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified V. sororia, a variable violet with differing flower colors and taxonomic treatments. Similar stemless violets and hybrids require additional characters; no cultivar, segregate taxon, or hybrid status is determined from these photographs. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
Basal, heart-shaped leaves and purple to white spring flowers arise on separate stalks. Later closed flowers can also produce seed. [N-viola-sororia](https://plants.ces.ncsu.edu/plants/viola-sororia/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Rabbits browse the plant, and birds and small mammals use its seeds. Wildlife use does not establish domestic-animal feeding safety. [N-viola-sororia](https://plants.ces.ncsu.edu/plants/viola-sororia/)
## Plants & habitat
Rhizomes and self-seeding allow it to spread in moist, fertile sites. It also supports bees and butterflies and may be welcome groundcover. [N-viola-sororia](https://plants.ces.ncsu.edu/plants/viola-sororia/)
## Management & timing
Confirm identity and decide whether a native patch can remain. For an unwanted lawn colony, CSU suggests removal when soil is moist; its advice covers wild violets as a group. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
*Evidence scope: Viola group management.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-viola-sororia** — [Viola sororia](https://plants.ces.ncsu.edu/plants/viola-sororia/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-blue-violet) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 85; Viola sororia. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is one member of CSU’s broader “Viola spp.” topic, not coverage of every Colorado violet. CNHP includes Viola sororia as native; photos and the profile do not resolve all members of the species complex.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-blue-violet-1 | Identification | Species-specific | N-viola-sororia | No quantitative safe exposure established here. |
| common-blue-violet-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-blue-violet-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-blue-violet-4 | Other animals | Species-specific | N-viola-sororia | No quantitative safe exposure established here. |
| common-blue-violet-5 | Plants & habitat | Species-specific | N-viola-sororia | No quantitative safe exposure established here. |
| common-blue-violet-6 | Management & timing | Viola group management | C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md
---
{
"id": "common-burdock",
"name": "Common burdock",
"scientific": "Arctium minus",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Burs and fine bristles injure animals",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-arctium-minus",
"S27",
"Fremont-list-definitions"
],
"description": "Common burdock: Burs and fine bristles injure animals. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-arctium-minus"
],
"scope": "Species-specific",
"note": "",
"id": "common-burdock-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-arctium-minus"
],
"scope": "Species-specific",
"note": "",
"id": "common-burdock-2"
},
{
"label": "People",
"sources": [
"N-arctium-minus"
],
"scope": "Species-specific",
"note": "",
"id": "common-burdock-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-arctium-minus"
],
"scope": "Species-specific",
"note": "",
"id": "common-burdock-4"
},
{
"label": "Other animals",
"sources": [
"N-arctium-minus"
],
"scope": "Species-specific",
"note": "",
"id": "common-burdock-5"
},
{
"id": "common-burdock-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/common-burdock.md"
}
---
# Common burdock
*Arctium minus*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Burs and fine bristles injure animals.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**bur** — Green spherical burs covered with long hooked bracts.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:ARCTIUM_MINUS_-_SANT_JUST_-_IB-233_(Repalassa).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/7/75/ARCTIUM_MINUS_-_SANT_JUST_-_IB-233_%28Repalassa%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Large branching plant with broad leaves and numerous small flower heads.
Photo: Alberto Salguero Quiles; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Arctium_minus_habito.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d9/Arctium_minus_habito.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Broad basal leaves showing a green upper surface and pale underside.
Photo: Alberto Salguero Quiles; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Arctium_minus_hoja_haz_y_env%C3%A9s.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/67/Arctium_minus_hoja_haz_y_env%C3%A9s.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A large-leaved biennial with purple flowerheads that mature into hooked burs. Leaf undersides are woolly. [N-arctium-minus](https://plants.ces.ncsu.edu/plants/arctium-minus/)
## Plants & habitat
Burs hitchhike on animals and clothing; persistent seeds and deep taproots make established patches difficult to remove. [N-arctium-minus](https://plants.ces.ncsu.edu/plants/arctium-minus/)
## People
Burs and tiny bristles can irritate eyes, skin and airways. Avoid breaking apart dry burs near the face. [N-arctium-minus](https://plants.ces.ncsu.edu/plants/arctium-minus/)
## Dogs & cats
The source specifically reports eye, skin and respiratory injury in dogs. Cats can also contact burs, but cat-specific outcomes were not assessed. [N-arctium-minus](https://plants.ces.ncsu.edu/plants/arctium-minus/)
## Other animals
Bristles can injure horses and livestock; burs can entangle small wildlife. [N-arctium-minus](https://plants.ces.ncsu.edu/plants/arctium-minus/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-arctium-minus** — [arctium minus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/arctium-minus/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-burdock) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-burdock-1 | Recognize | Species-specific | N-arctium-minus | No quantitative safe exposure established here. |
| common-burdock-2 | Plants & habitat | Species-specific | N-arctium-minus | No quantitative safe exposure established here. |
| common-burdock-3 | People | Species-specific | N-arctium-minus | No quantitative safe exposure established here. |
| common-burdock-4 | Dogs & cats | Species-specific | N-arctium-minus | No quantitative safe exposure established here. |
| common-burdock-5 | Other animals | Species-specific | N-arctium-minus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/index.md
---
{
"id": "common-chickweed",
"name": "Common chickweed",
"scientific": "Stellaria media",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A cool-season weed that can seed while still small",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Common chickweed is not every plant called chickweed. Species identification and contamination history must be established independently of any food-use claim.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-stellaria-media",
"S27"
],
"description": "Common chickweed: A cool-season weed that can seed while still small. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-stellaria-media"
],
"scope": "Species-specific",
"note": "",
"id": "common-chickweed-1"
},
{
"label": "People",
"sources": [
"N-stellaria-media"
],
"scope": "Species-specific",
"note": "",
"id": "common-chickweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-chickweed-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-chickweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-stellaria-media"
],
"scope": "Species-specific",
"note": "",
"id": "common-chickweed-5"
},
{
"label": "Management & timing",
"sources": [
"N-stellaria-media"
],
"scope": "Species-specific",
"note": "",
"id": "common-chickweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-chickweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-chickweed-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-chickweed-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 81; Stellaria media",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Stellaria media"
},
"source": "content/plants/common-chickweed.md"
}
---
# Common chickweed
*Stellaria media*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A cool-season weed that can seed while still small.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Common chickweed is not every plant called chickweed. Species identification and contamination history must be established independently of any food-use claim.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower and leaves** — A small flowering shoot held on a glove, showing white deeply divided petals, opposite leaves and buds.
Photo: Forest and Kim Starr; [CC BY 3.0 us](https://creativecommons.org/licenses/by/3.0/us/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Starr-110519-5604-Stellaria_media-flowers_and_leaves-Hawea_Pl_Olinda-Maui_(24468570313).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/86/Starr-110519-5604-Stellaria_media-flowers_and_leaves-Hawea_Pl_Olinda-Maui_%2824468570313%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Stellaria media belongs to a complex with similar chickweeds. Identification follows the source; a single flower or seedling view alone may not distinguish every member. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — A dense low mat of green chickweed foliage dotted with small white flowers.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/73290170); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/119633725/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Stellaria media belongs to a complex with similar chickweeds. Identification follows the source; a single flower or seedling view alone may not distinguish every member. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruits and seeds** — Dried capsules and numerous small brown seeds arranged on a pale background; the source includes a 1 cm scale.
Photo: Roger Culos; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Stellaria_media_MHNT.BOT.2008.1.33.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/71/Stellaria_media_MHNT.BOT.2008.1.33.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Stellaria media belongs to a complex with similar chickweeds. Identification follows the source; a single flower or seedling view alone may not distinguish every member. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A soft, spreading annual with opposite oval leaves and small white flowers. Five deeply split petals look like ten. A line of hairs runs along the stems. [N-stellaria-media](https://plants.ces.ncsu.edu/plants/stellaria-media/)
## People
The source reports saponins in the leaves alongside food uses. This profile does not establish a safe portion or identify a plant for foraging. [N-stellaria-media](https://plants.ces.ncsu.edu/plants/stellaria-media/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It can root at stem joints and reseed quickly in moist, fertile ground. It also provides food and habitat for insects and birds. [N-stellaria-media](https://plants.ces.ncsu.edu/plants/stellaria-media/)
## Management & timing
Look for small plants during cool weather. Shallow roots make young patches relatively easy to pull; remove them before further seed production. [N-stellaria-media](https://plants.ces.ncsu.edu/plants/stellaria-media/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-stellaria-media** — [Stellaria media](https://plants.ces.ncsu.edu/plants/stellaria-media/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-chickweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 81; Stellaria media. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Common chickweed is not every plant called chickweed. Species identification and contamination history must be established independently of any food-use claim.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-chickweed-1 | Identification | Species-specific | N-stellaria-media | No quantitative safe exposure established here. |
| common-chickweed-2 | People | Species-specific | N-stellaria-media | No quantitative safe exposure established here. |
| common-chickweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-chickweed-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-chickweed-5 | Plants & habitat | Species-specific | N-stellaria-media | No quantitative safe exposure established here. |
| common-chickweed-6 | Management & timing | Species-specific | N-stellaria-media | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md
---
{
"id": "common-cocklebur",
"name": "Common cocklebur",
"scientific": "Xanthium strumarium",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Burs catch in fur; seedlings and seeds are hazardous",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Xanthium strumarium is treated broadly by some sources and split into other taxa by others. Photographs retain their original source identifications. Native status and a local specimen’s exact taxon need separate review.",
"source_ids": [
"CO-rules-2025",
"N-xanthium-strumarium",
"S27"
],
"description": "Common cocklebur: Burs catch in fur; seedlings and seeds are hazardous. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-xanthium-strumarium"
],
"scope": "Species-specific",
"note": "",
"id": "common-cocklebur-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-xanthium-strumarium"
],
"scope": "Species-specific",
"note": "",
"id": "common-cocklebur-2"
},
{
"label": "People",
"sources": [
"N-xanthium-strumarium"
],
"scope": "Source warning; human clinical detail limited",
"note": "",
"id": "common-cocklebur-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-xanthium-strumarium"
],
"scope": "Physical-risk inference and general animal warning",
"note": "",
"id": "common-cocklebur-4"
},
{
"label": "Other animals",
"sources": [
"N-xanthium-strumarium"
],
"scope": "Species-specific",
"note": "",
"id": "common-cocklebur-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-cocklebur-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-cocklebur.md"
}
---
# Common cocklebur
*Xanthium strumarium*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Burs catch in fur; seedlings and seeds are hazardous.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Xanthium strumarium is treated broadly by some sources and split into other taxa by others. Photographs retain their original source identifications. Native status and a local specimen’s exact taxon need separate review.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf** — Broad triangular to shallowly lobed leaf with coarse teeth and prominent veins.
Photo: Franco Folini; [CC BY 2.5](https://creativecommons.org/licenses/by/2.5); [source record](https://commons.wikimedia.org/wiki/File:Xanthium_strumarium_001.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5d/Xanthium_strumarium_001.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cocklebur taxonomy varies by flora and Xanthium strumarium is often used broadly. Related X. orientale-group plants have historically been included. These are source-identified X. strumarium references; one bur is explicitly labeled sensu stricto. General foliage or habit does not independently resolve the complex or establish the identity of Colorado plants. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Branching plant with broad petioled leaves and inconspicuous axillary clusters.
Photo: Stan Shebs; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Xanthium_strumarium_7.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/79/Xanthium_strumarium_7.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cocklebur taxonomy varies by flora and Xanthium strumarium is often used broadly. Related X. orientale-group plants have historically been included. These are source-identified X. strumarium references; one bur is explicitly labeled sensu stricto. General foliage or habit does not independently resolve the complex or establish the identity of Colorado plants. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**bur** — Dry oval cocklebur with hooked spines and terminal beaks, photographed with a scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Xanthium_strumarium_s._str._sl3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/29/Xanthium_strumarium_s._str._sl3.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cocklebur taxonomy varies by flora and Xanthium strumarium is often used broadly. Related X. orientale-group plants have historically been included. These are source-identified X. strumarium references; one bur is explicitly labeled sensu stricto. General foliage or habit does not independently resolve the complex or establish the identity of Colorado plants. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A summer annual with rough, broad leaves and hard burs covered in hooked prickles. [N-xanthium-strumarium](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/)
## Plants & habitat
Can form colonies in fields and wet disturbed ground. Hooked burs move on animals and clothing. [N-xanthium-strumarium](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/)
## People
NC State flags human poisoning but provides primarily animal clinical descriptions. Do not infer a human dose or identical symptoms. [N-xanthium-strumarium](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/)
*Evidence scope: Source warning; human clinical detail limited.*
## Dogs & cats
Burs attach to fur and can cause contact problems. Animal ingestion warnings do not establish dog- or cat-specific thresholds; prevent chewing seedlings, seeds and burs. [N-xanthium-strumarium](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/)
*Evidence scope: Physical-risk inference and general animal warning.*
## Other animals
Seedling cotyledons and seeds are the principal ingestion concern. The source describes low blood sugar, weakness, spasms and potentially fatal poisoning. [N-xanthium-strumarium](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-xanthium-strumarium** — [xanthium strumarium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-cocklebur) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Xanthium strumarium is treated broadly by some sources and split into other taxa by others. Photographs retain their original source identifications. Native status and a local specimen’s exact taxon need separate review.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-cocklebur-1 | Recognize | Species-specific | N-xanthium-strumarium | No quantitative safe exposure established here. |
| common-cocklebur-2 | Plants & habitat | Species-specific | N-xanthium-strumarium | No quantitative safe exposure established here. |
| common-cocklebur-3 | People | Source warning; human clinical detail limited | N-xanthium-strumarium | No quantitative safe exposure established here. |
| common-cocklebur-4 | Dogs & cats | Physical-risk inference and general animal warning | N-xanthium-strumarium | No quantitative safe exposure established here. |
| common-cocklebur-5 | Other animals | Species-specific | N-xanthium-strumarium | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/index.md
---
{
"id": "common-crupina",
"name": "Common crupina",
"scientific": "Crupina vulgaris",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Dense stands reduce forage",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Washington source used for biology; Colorado’s current rules supply the legal designation. “Not known toxic” in the source is not a feeding-safety assessment.",
"source_ids": [
"CO-rules-2025",
"WA-common-crupina",
"S27",
"Fremont-list-definitions"
],
"description": "Common crupina: Dense stands reduce forage. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-common-crupina"
],
"scope": "Species-specific",
"note": "",
"id": "common-crupina-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-common-crupina"
],
"scope": "Species-specific",
"note": "",
"id": "common-crupina-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-crupina-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-crupina-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-crupina-5"
},
{
"id": "common-crupina-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-crupina-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-crupina-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-crupina-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/common-crupina.md"
}
---
# Common crupina
*Crupina vulgaris*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Dense stands reduce forage.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Washington source used for biology; Colorado’s current rules supply the legal designation. “Not known toxic” in the source is not a feeding-safety assessment.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**seed head** — An open fruiting head with conspicuous dark bristles.
Photo: Clément Maouche; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/284022563); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/510411466/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seeds** — Two detached fruits with dark, bristly pappus hairs, resting on a palm.
Photo: Clément Maouche; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/284022563); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/510411459/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering habit** — Slender upright stems with elongated flower heads and a mature fruiting head; other plants occur in the background.
Photo: Clément Maouche; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/284022563); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/510412740/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A winter annual with finely divided, bristly leaves and narrow, vase-shaped purple flowerheads. [WA-common-crupina](https://www.nwcb.wa.gov/weeds/common-crupina)
## Plants & habitat
Reproduces from seed and can form dense stands that reduce available livestock forage. [WA-common-crupina](https://www.nwcb.wa.gov/weeds/common-crupina)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-common-crupina** — [Common Crupina](https://www.nwcb.wa.gov/weeds/common-crupina), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:08:59+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-crupina) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Washington source used for biology; Colorado’s current rules supply the legal designation. “Not known toxic” in the source is not a feeding-safety assessment.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-crupina-1 | Recognize | Species-specific | WA-common-crupina | No quantitative safe exposure established here. |
| common-crupina-2 | Plants & habitat | Species-specific | WA-common-crupina | No quantitative safe exposure established here. |
| common-crupina-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-crupina-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-crupina-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md
---
{
"id": "common-dandelion",
"name": "Common dandelion",
"scientific": "Taraxacum officinale",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Persistent lawn volunteer; sap can irritate skin",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.",
"source_ids": [
"CO-rules-2025",
"N-taraxacum-officinale",
"C-descriptions",
"S27"
],
"description": "Common dandelion: Persistent lawn volunteer; sap can irritate skin. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-taraxacum-officinale"
],
"scope": "Species-specific",
"note": "",
"id": "common-dandelion-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions",
"N-taraxacum-officinale"
],
"scope": "Species-specific",
"note": "",
"id": "common-dandelion-2"
},
{
"label": "People",
"sources": [
"N-taraxacum-officinale"
],
"scope": "Species-specific",
"note": "",
"id": "common-dandelion-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-dandelion-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-dandelion-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-dandelion-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-dandelion-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-dandelion-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-dandelion.md"
}
---
# Common dandelion
*Taraxacum officinale*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Persistent lawn volunteer; sap can irritate skin.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Whole photographed plant with a taproot, basal lobed leaves, and a leafless stalk bearing a yellow flower head.
Photo: FoeNyx; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Taraxacum-officinalis-plant.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/11/Taraxacum-officinalis-plant.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seed-head** — Rounded white seed head of many fruits, each attached to a radiating stalk and parachute-like pappus.
Photo: Michael Gäbler; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Ripe_fruits_by_Common_Dandelion.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/65/Ripe_fruits_by_Common_Dandelion.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Bright yellow flower heads made of many strap-shaped florets, with unopened buds and basal foliage nearby.
Photo: Slick (German Wikipedia); [Public domain](https://commons.wikimedia.org/wiki/File:Taraxacum_officinale_flower_2005-05-01.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Taraxacum_officinale_flower_2005-05-01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/dc/Taraxacum_officinale_flower_2005-05-01.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A basal rosette of toothed leaves, single yellow heads on hollow leafless stalks, and a rounded puffball of windborne seeds. [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)
## Plants & habitat
A familiar Colorado lawn plant with a persistent taproot. Flowers provide early pollen and nectar; removal is a site choice, not a claim that it has no ecological value. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)
## People
Sap can cause contact dermatitis in susceptible people. Recorded food uses do not establish that an unidentified or treated lawn plant is safe to eat. [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-taraxacum-officinale** — [taraxacum officinale — Plant Toolbox](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-dandelion) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-dandelion-1 | Recognize | Species-specific | N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-2 | Plants & habitat | Species-specific | C-descriptions, N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-3 | People | Species-specific | N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-dandelion-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/index.md
---
{
"id": "common-lambsquarters",
"name": "Common lambsquarters",
"scientific": "Chenopodium album",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Prolific garden weed; ingestion caution",
"warning_tone": "caution",
"aliases": [
"white goosefoot",
"lamb’s quarters"
],
"taxonomy_note": "Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.",
"source_ids": [
"CO-rules-2025",
"N-chenopodium-album",
"C-edible-weeds",
"S27"
],
"description": "Common lambsquarters: Prolific garden weed; ingestion caution. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-chenopodium-album"
],
"scope": "Species-specific",
"note": "",
"id": "common-lambsquarters-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-edible-weeds",
"N-chenopodium-album"
],
"scope": "Species-specific",
"note": "",
"id": "common-lambsquarters-2"
},
{
"label": "People",
"sources": [
"N-chenopodium-album"
],
"scope": "Species-specific",
"note": "",
"id": "common-lambsquarters-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-lambsquarters-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-lambsquarters-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-lambsquarters-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-lambsquarters-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-lambsquarters.md"
}
---
# Common lambsquarters
*Chenopodium album*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Prolific garden weed; ingestion caution.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf** — A broad-based, toothed leaf on an upright leafy stem.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_-_3714283761.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c5/Chenopodium_album_-_3714283761.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**reproductive clusters** — Close view of compact, mealy green and reddish reproductive clusters along the stem.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_-_4031382321.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/08/Chenopodium_album_-_4031382321.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seedling** — A very young seedling with two narrow cotyledons emerging from dark soil.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_2018-05-02_0061.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b4/Chenopodium_album_2018-05-02_0061.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual with variable goosefoot-shaped leaves, a whitish mealy coating on young growth and small green flower clusters. [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)
## Plants & habitat
Pueblo County Extension identifies C. album among common Colorado weeds. Many persistent seeds allow repeated emergence after disturbance. [C-edible-weeds](https://pueblo.extension.colostate.edu/early-spring-edible-plants-in-your-yard-and-garden/) [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)
## People
NC State reports digestive and nervous-system effects after large ingestion and notes oxalic acid and saponins. Food-use records are not a safe-dose recommendation. [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-chenopodium-album** — [chenopodium album — Plant Toolbox](https://plants.ces.ncsu.edu/plants/chenopodium-album/), NC State Extension. Accessed 2026-09-07T01:21:10+00:00. Locator: Species identity, description, ecology, toxicity.
- **C-edible-weeds** — [Early Spring Edible Plants In Your Yard And Garden](https://pueblo.extension.colostate.edu/early-spring-edible-plants-in-your-yard-and-garden/), Colorado State University Extension, Pueblo County. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-lambsquarters) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-lambsquarters-1 | Recognize | Species-specific | N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-2 | Plants & habitat | Species-specific | C-edible-weeds, N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-3 | People | Species-specific | N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-lambsquarters-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/index.md
---
{
"id": "common-mallow",
"name": "Common mallow",
"scientific": "Malva neglecta",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Tough taproot and persistent lawn seedbank",
"warning_tone": "caution",
"aliases": [
"cheeseweed",
"buttonweed"
],
"taxonomy_note": "Common names overlap with other Malva species. The reviewed account supports weed biology, not a declaration that all pet or livestock exposures are harmless.",
"source_ids": [
"CO-rules-2025",
"N-malva-neglecta",
"C-descriptions",
"S27"
],
"description": "Common mallow: Tough taproot and persistent lawn seedbank. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-malva-neglecta",
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "common-mallow-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions",
"N-malva-neglecta"
],
"scope": "Species-specific",
"note": "",
"id": "common-mallow-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mallow-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mallow-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mallow-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-mallow-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-mallow-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-mallow-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-mallow.md"
}
---
# Common mallow
*Malva neglecta*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Tough taproot and persistent lawn seedbank.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Common names overlap with other Malva species. The reviewed account supports weed biology, not a declaration that all pet or livestock exposures are harmless.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers and leaves** — A small pale flower beneath rounded, shallowly lobed leaves with toothed edges.
Photo: NY State IPM Program at Cornell University from New York, USA; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Malva_neglecta_-_leaf,_inflorescence_(19059303085).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c7/Malva_neglecta_-_leaf%2C_inflorescence_%2819059303085%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Other mallows can have similar leaves and flowers. Identification follows the exact scientific source label; no close-relative placeholder was used. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A dense spreading patch of rounded, shallowly lobed leaves.
Photo: NY State IPM Program at Cornell University from New York, USA; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Malva_neglecta_-_whole_plant_(18438619353).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bd/Malva_neglecta_-_whole_plant_%2818438619353%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Other mallows can have similar leaves and flowers. Identification follows the exact scientific source label; no close-relative placeholder was used. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — A pale pink flower with five notched petals and a central column, among rounded leaves.
Photo: Daniel Ballmer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Malva_neglecta_Bl%C3%BCte.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6d/Malva_neglecta_Bl%C3%BCte.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Other mallows can have similar leaves and flowers. Identification follows the exact scientific source label; no close-relative placeholder was used. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Low spreading stems, rounded shallowly lobed leaves and small pale flowers with notched petals; fruits resemble little cheese wheels. [N-malva-neglecta](https://plants.ces.ncsu.edu/plants/malva-neglecta/) [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Plants & habitat
Common in disturbed Colorado gardens and thin lawns. Taproots become difficult to remove, and durable seeds support recurring patches. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-malva-neglecta](https://plants.ces.ncsu.edu/plants/malva-neglecta/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-malva-neglecta** — [malva neglecta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/malva-neglecta/), NC State Extension. Accessed 2026-09-07T01:21:11+00:00. Locator: Species identity, description, ecology, toxicity.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-mallow) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Common names overlap with other Malva species. The reviewed account supports weed biology, not a declaration that all pet or livestock exposures are harmless.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-mallow-1 | Recognize | Species-specific | N-malva-neglecta, C-descriptions | No quantitative safe exposure established here. |
| common-mallow-2 | Plants & habitat | Species-specific | C-descriptions, N-malva-neglecta | No quantitative safe exposure established here. |
| common-mallow-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-mallow-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-mallow-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/index.md
---
{
"id": "common-mullein",
"name": "Common mullein",
"scientific": "Verbascum thapsus",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Dense rosettes and persistent volunteers",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Soft leaves do not establish medicinal or ingestion safety. This is not lamb’s-ear (Stachys byzantina).",
"source_ids": [
"CO-rules-2025",
"N-verbascum-thapsus",
"S27",
"Fremont-list-definitions"
],
"description": "Common mullein: Dense rosettes and persistent volunteers. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-verbascum-thapsus"
],
"scope": "Species-specific",
"note": "",
"id": "common-mullein-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-verbascum-thapsus"
],
"scope": "Species-specific",
"note": "",
"id": "common-mullein-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mullein-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mullein-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-mullein-5"
},
{
"id": "common-mullein-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-mullein-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-mullein-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-mullein-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/common-mullein.md"
}
---
# Common mullein
*Verbascum thapsus*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Dense rosettes and persistent volunteers.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Soft leaves do not establish medicinal or ingestion safety. This is not lamb’s-ear (Stachys byzantina).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Tall yellow flowering spike above a column of broad pale woolly leaves.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:VERBASCUM_THAPSUS_-_B%C3%92FIA_-_IB-957_(Blenera).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e6/VERBASCUM_THAPSUS_-_B%C3%92FIA_-_IB-957_%28Blenera%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Small yellow flowers and pale woolly buds crowd a dense upright spike.
Photo: Fritz Geller-Grimm; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Schwanheimer_Duene_fg14.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fd/Schwanheimer_Duene_fg14.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**rosette** — Young basal rosette of thick oval gray-green leaves covered in soft woolly hairs.
Photo: Borealis55; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Verbascum_thapsus_5799.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/48/Verbascum_thapsus_5799.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other mullein species and hybrids can resemble V. thapsus. Source-labeled V. phlomoides photographs found in gallery searches were not selected. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A woolly leaf rosette produces a tall, dense spike of yellow flowers, typically in its second year. [N-verbascum-thapsus](https://plants.ces.ncsu.edu/plants/verbascum-thapsus/)
## Plants & habitat
Self-seeds in dry, disturbed places and can crowd neighboring vegetation. Prevent seed formation where control is needed. [N-verbascum-thapsus](https://plants.ces.ncsu.edu/plants/verbascum-thapsus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-verbascum-thapsus** — [verbascum thapsus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/verbascum-thapsus/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-mullein) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Soft leaves do not establish medicinal or ingestion safety. This is not lamb’s-ear (Stachys byzantina).
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-mullein-1 | Recognize | Species-specific | N-verbascum-thapsus | No quantitative safe exposure established here. |
| common-mullein-2 | Plants & habitat | Species-specific | N-verbascum-thapsus | No quantitative safe exposure established here. |
| common-mullein-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-mullein-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-mullein-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/index.md
---
{
"id": "common-purslane",
"name": "Common purslane",
"scientific": "Portulaca oleracea",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Pet ingestion hazard despite human food uses",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Distinguish succulent purslane from low-growing spurges. The ASPCA entry is Portulaca oleracea, not merely an ornamental plant sharing a common name.",
"source_ids": [
"CO-rules-2025",
"N-portulaca-oleracea",
"C-descriptions",
"A-purslane",
"S27"
],
"description": "Common purslane: Pet ingestion hazard despite human food uses. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-portulaca-oleracea"
],
"scope": "Species-specific",
"note": "",
"id": "common-purslane-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions",
"N-portulaca-oleracea"
],
"scope": "Species-specific",
"note": "",
"id": "common-purslane-2"
},
{
"label": "People",
"sources": [
"N-portulaca-oleracea"
],
"scope": "Food-use record, not individual safety assessment",
"note": "",
"id": "common-purslane-3"
},
{
"label": "Dogs & cats",
"sources": [
"A-purslane"
],
"scope": "Species-specific",
"note": "",
"id": "common-purslane-4"
},
{
"label": "Other animals",
"sources": [
"A-purslane"
],
"scope": "Species-specific",
"note": "",
"id": "common-purslane-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-purslane.md"
}
---
# Common purslane
*Portulaca oleracea*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Pet ingestion hazard despite human food uses.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinguish succulent purslane from low-growing spurges. The ASPCA entry is Portulaca oleracea, not merely an ornamental plant sharing a common name.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — Small yellow flowers nestled among thick rounded succulent leaves.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:PORTULACA_OLERACEA_-_EMPALOUS_-_IB-518_(Verdolaga).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/1/19/PORTULACA_OLERACEA_-_EMPALOUS_-_IB-518_%28Verdolaga%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common purslane is a taxonomically variable aggregate. General photographs do not determine an infraspecific taxon or seed-based microspecies. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-stem** — Fleshy oval green leaves cluster along smooth reddish prostrate stems.
Photo: Forest & Kim Starr; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Starr_060406-7304_Portulaca_oleracea.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e9/Starr_060406-7304_Portulaca_oleracea.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common purslane is a taxonomically variable aggregate. General photographs do not determine an infraspecific taxon or seed-based microspecies. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Low mat with radiating reddish stems over bare sandy soil.
Photo: Javier martin; [Public domain](https://commons.wikimedia.org/wiki/File:Portulaca_oleracea_habitusDehesaBoyalPuertollano.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Portulaca_oleracea_habitusDehesaBoyalPuertollano.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/da/Portulaca_oleracea_habitusDehesaBoyalPuertollano.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common purslane is a taxonomically variable aggregate. General photographs do not determine an infraspecific taxon or seed-based microspecies. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Low, spreading red-tinged stems, fleshy leaves and small yellow flowers. [N-portulaca-oleracea](https://plants.ces.ncsu.edu/plants/portulaca-oleracea/)
## Plants & habitat
A familiar Colorado garden weed. Seeds and surviving stem pieces can sustain a patch. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-portulaca-oleracea](https://plants.ces.ncsu.edu/plants/portulaca-oleracea/)
## People
The species has documented human food uses, but this guide provides neither a foraging identification nor a safe serving amount. Do not transfer food-use claims to pets. [N-portulaca-oleracea](https://plants.ces.ncsu.edu/plants/portulaca-oleracea/)
*Evidence scope: Food-use record, not individual safety assessment.*
## Dogs & cats
ASPCA lists this exact species as toxic to dogs and cats because of soluble oxalates. Contact a veterinarian after suspected ingestion. [A-purslane](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/purslane)
## Other animals
ASPCA also lists horses. No safe forage amount is established here. [A-purslane](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/purslane)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-portulaca-oleracea** — [portulaca oleracea — Plant Toolbox](https://plants.ces.ncsu.edu/plants/portulaca-oleracea/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **A-purslane** — [Purslane](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/purslane), ASPCA Poison Control. Accessed 2026-09-07T01:14:01+00:00. Locator: Scientific name, toxicity to dogs, cats and horses.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-purslane) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Distinguish succulent purslane from low-growing spurges. The ASPCA entry is Portulaca oleracea, not merely an ornamental plant sharing a common name.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-purslane-1 | Recognize | Species-specific | N-portulaca-oleracea | No quantitative safe exposure established here. |
| common-purslane-2 | Plants & habitat | Species-specific | C-descriptions, N-portulaca-oleracea | No quantitative safe exposure established here. |
| common-purslane-3 | People | Food-use record, not individual safety assessment | N-portulaca-oleracea | No quantitative safe exposure established here. |
| common-purslane-4 | Dogs & cats | Species-specific | A-purslane | No quantitative safe exposure established here. |
| common-purslane-5 | Other animals | Species-specific | A-purslane | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md
---
{
"id": "common-ragweed",
"name": "Common ragweed",
"scientific": "Ambrosia artemisiifolia",
"category": "native",
"status": "Colorado native",
"status_sources": [
"N-ambrosia-artemisiifolia"
],
"warning": "Pollen allergy; skin irritation",
"warning_tone": "caution",
"aliases": [
"hay fever weed"
],
"taxonomy_note": "",
"source_ids": [
"N-ambrosia-artemisiifolia"
],
"description": "Common ragweed: Pollen allergy; skin irritation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-ambrosia-artemisiifolia"
],
"scope": "Species-specific",
"note": "",
"id": "common-ragweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-ambrosia-artemisiifolia"
],
"scope": "Species-specific",
"note": "",
"id": "common-ragweed-2"
},
{
"label": "People",
"sources": [
"N-ambrosia-artemisiifolia"
],
"scope": "Species-specific",
"note": "",
"id": "common-ragweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "common-ragweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "This review did not establish species-specific livestock toxicity.",
"id": "common-ragweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-ragweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-ragweed-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-ragweed.md"
}
---
# Common ragweed
*Ambrosia artemisiifolia*
**Colorado native.** [N-ambrosia-artemisiifolia](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/)
> **Pollen allergy; skin irritation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit and habitat** — A low stand of common ragweed flowering along the edge of a paved path, with other vegetation nearby.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_artemisiifolia_15-p.bot-ambro.arte-49.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b3/Ambrosia_artemisiifolia_15-p.bot-ambro.arte-49.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaves** — Several deeply divided green ragweed leaves viewed from above.
Photo: Meneerke bloem; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_artemisiifolia_leaf.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c9/Ambrosia_artemisiifolia_leaf.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of a terminal raceme of small green male flower heads; the source photo includes a 5 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_artemisiifolia_sl6.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e7/Ambrosia_artemisiifolia_sl6.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual with deeply divided, fern-like leaves and inconspicuous green flower spikes. [N-ambrosia-artemisiifolia](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/)
## Plants & habitat
A dry-site volunteer that produces many persistent seeds; birds eat its seeds. Remove unwanted plants before flowering and seed set. [N-ambrosia-artemisiifolia](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/)
## People
Windborne pollen is a major cause of hay fever; contact dermatitis is also reported. [N-ambrosia-artemisiifolia](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/)
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
This review did not establish species-specific livestock toxicity. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-ambrosia-artemisiifolia** — [Ambrosia artemisiifolia — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/), NC State Extension. Accessed 2026-09-07T00:23:56+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-ragweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| common-ragweed-1 | Recognize | Species-specific | N-ambrosia-artemisiifolia | No quantitative exposure threshold established here. |
| common-ragweed-2 | Plants & habitat | Species-specific | N-ambrosia-artemisiifolia | No quantitative exposure threshold established here. |
| common-ragweed-3 | People | Species-specific | N-ambrosia-artemisiifolia | No quantitative exposure threshold established here. |
| common-ragweed-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| common-ragweed-5 | Other animals | Review limitation | Review limitation | This review did not establish species-specific livestock toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md
---
{
"id": "common-st-johnswort",
"name": "Common St. Johnswort",
"scientific": "Hypericum perforatum",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Photosensitivity and animal exposure concerns",
"warning_tone": "danger",
"aliases": [
"St John’s wort",
"Klamath weed"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-hypericum-perforatum",
"S27",
"Fremont-list-definitions"
],
"description": "Common St. Johnswort: Photosensitivity and animal exposure concerns. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-hypericum-perforatum"
],
"scope": "Species-specific",
"note": "",
"id": "common-st-johnswort-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-hypericum-perforatum"
],
"scope": "Species-specific",
"note": "",
"id": "common-st-johnswort-2"
},
{
"label": "People",
"sources": [
"N-hypericum-perforatum"
],
"scope": "Species-specific",
"note": "",
"id": "common-st-johnswort-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-hypericum-perforatum"
],
"scope": "Species-specific",
"note": "",
"id": "common-st-johnswort-4"
},
{
"label": "Other animals",
"sources": [
"N-hypericum-perforatum"
],
"scope": "Species-specific",
"note": "",
"id": "common-st-johnswort-5"
},
{
"id": "common-st-johnswort-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-st-johnswort-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/common-st-johnswort.md"
}
---
# Common St. Johnswort
*Hypericum perforatum*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Photosensitivity and animal exposure concerns.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — Five-petaled yellow flowers with numerous projecting stamens.
Photo: W. Bulach; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:.00_3738_St._John%27s_wort_(Hypericum_perforatum).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/68/.00_3738_St._John%27s_wort_%28Hypericum_perforatum%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Erect branching stems with clusters of yellow flowers amid green foliage.
Photo: Sten Porse; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Hypericon-perforatum.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2f/Hypericon-perforatum.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Backlit oval leaf showing numerous translucent pale gland dots and darker marginal dots.
Photo: Michael Gasperl (Migas); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Hypericum-perforatum(Blatt).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/cf/Hypericum-perforatum%28Blatt%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow five-petaled flowers with many stamens; small opposite leaves show translucent dots when backlit. [N-hypericum-perforatum](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/)
## Plants & habitat
Seeds and spreading underground stems create persistent patches that can displace native plants. [N-hypericum-perforatum](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/)
## People
Hypericin-containing plant material can cause photosensitivity and dermatitis. The guide does not assess herbal use or medication interactions. [N-hypericum-perforatum](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/)
## Dogs & cats
NC State flags dogs and cats. This source does not establish a pet-specific safe amount. [N-hypericum-perforatum](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/)
## Other animals
Horses are also flagged by the source. Seek veterinary advice before allowing access to contaminated forage. [N-hypericum-perforatum](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-hypericum-perforatum** — [hypericum perforatum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-st-johnswort) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-st-johnswort-1 | Recognize | Species-specific | N-hypericum-perforatum | No quantitative safe exposure established here. |
| common-st-johnswort-2 | Plants & habitat | Species-specific | N-hypericum-perforatum | No quantitative safe exposure established here. |
| common-st-johnswort-3 | People | Species-specific | N-hypericum-perforatum | No quantitative safe exposure established here. |
| common-st-johnswort-4 | Dogs & cats | Species-specific | N-hypericum-perforatum | No quantitative safe exposure established here. |
| common-st-johnswort-5 | Other animals | Species-specific | N-hypericum-perforatum | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/index.md
---
{
"id": "common-sunflower",
"name": "Common sunflower",
"scientific": "Helianthus annuus",
"category": "native",
"status": "Colorado native",
"status_sources": [
"S28",
"S23"
],
"warning": "Listed non-toxic to dogs & cats",
"warning_tone": "neutral",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S28",
"S23",
"S24",
"S25"
],
"description": "Common sunflower: Listed non-toxic to dogs & cats. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S23"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-sunflower-1"
},
{
"label": "Plants & habitat",
"sources": [
"S23"
],
"scope": "Species-specific + garden judgment",
"note": "Crowding advice is an inference from vigorous self-seeding; no chemical harm to neighboring plants is asserted.",
"reviewed": "2026-09-06",
"id": "common-sunflower-2"
},
{
"label": "People",
"sources": [],
"scope": "Not assessed",
"note": "Editorial limit on scope; no claim of human safety.",
"reviewed": "2026-09-06",
"id": "common-sunflower-3"
},
{
"label": "Dogs & cats",
"sources": [
"S24",
"S25"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-sunflower-4"
},
{
"label": "Other animals",
"sources": [
"S23",
"S24"
],
"scope": "Species-specific; livestock not assessed",
"note": "",
"reviewed": "2026-09-06",
"id": "common-sunflower-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"common-sunflower-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-sunflower-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-sunflower.md"
}
---
# Common sunflower
*Helianthus annuus*
**Colorado native.** [S28](https://pueblo.extension.colostate.edu/loving-our-native-plants/) [S23](https://plants.ces.ncsu.edu/plants/helianthus-annuus/)
> **Listed non-toxic to dogs & cats.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower head** — Front view of a sunflower head, showing yellow ray florets surrounding the darker central disk.
Photo: Michelle W. （鍾偉瑋）; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/61287321); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/98056702/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**back of flower head** — Side and rear view of a sunflower head, showing green involucral bracts and a densely hairy stem.
Photo: lanechaffin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/28073080); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/43735811/original.jpg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers and leaves** — A yellow sunflower head on a leafy shoot with broad, toothed leaves.
Photo: Michelle W. （鍾偉瑋）; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/124078954); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/210274752/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual with rough, hairy stems and yellow flower rays around darker central disks. [S23](https://plants.ces.ncsu.edu/plants/helianthus-annuus/)
## Plants & habitat
Readily self-seeds and can become weedy. Garden judgment: thin unwanted volunteers where they crowd other plants. [S23](https://plants.ces.ncsu.edu/plants/helianthus-annuus/)
## People
Human ingestion safety is not evaluated in this guide. This profile is not a recommendation to forage.
## Dogs & cats
ASPCA explicitly lists common sunflower as non-toxic to dogs and cats. Any plant material can still upset a pet’s stomach. [S24](https://www.aspca.org/news/plants-support-your-local-wildlife) [S25](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants)
## Other animals
Seeds feed birds and squirrels. Livestock safety is not established by the dog-and-cat source. [S23](https://plants.ces.ncsu.edu/plants/helianthus-annuus/) [S24](https://www.aspca.org/news/plants-support-your-local-wildlife)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S28** — [Loving Our Native Plants](https://pueblo.extension.colostate.edu/loving-our-native-plants/), CSU Extension · Pueblo County. Accessed 2026-09-07T00:23:56+00:00. Locator: Native landscape plant list: Common sunflower and Showy milkweed.
- **S23** — [Helianthus annuus](https://plants.ces.ncsu.edu/plants/helianthus-annuus/), NC State Extension · Plant Toolbox. Accessed 2026-09-07T00:23:56+00:00. Locator: Description; distribution; self-seeding; Wildlife Value.
- **S24** — [Plants to Support Your Local Wildlife](https://www.aspca.org/news/plants-support-your-local-wildlife), ASPCA Poison Control. Accessed 2026-09-07T00:23:56+00:00. Locator: Plants that are non-toxic to dogs and cats: common sunflower (Helianthus annuus).
- **S25** — [Toxic and Non-Toxic Plants](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants), ASPCA Poison Control. Accessed 2026-09-07T00:23:56+00:00. Locator: Any plant material may cause vomiting or gastrointestinal upset; database limitations.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-sunflower) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| common-sunflower-1 | Recognize | Species-specific | S23 | No quantitative exposure threshold established here. |
| common-sunflower-2 | Plants & habitat | Species-specific + garden judgment | S23 | Crowding advice is an inference from vigorous self-seeding; no chemical harm to neighboring plants is asserted. |
| common-sunflower-3 | People | Not assessed | Review limitation | Editorial limit on scope; no claim of human safety. |
| common-sunflower-4 | Dogs & cats | Species-specific | S24, S25 | No quantitative exposure threshold established here. |
| common-sunflower-5 | Other animals | Species-specific; livestock not assessed | S23, S24 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/index.md
---
{
"id": "common-tansy",
"name": "Common tansy",
"scientific": "Tanacetum vulgare",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Toxic ingestion; contact dermatitis",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Common tansy is not tansy ragwort (Jacobaea vulgaris). Their chemical hazards and flower structures differ.",
"source_ids": [
"CO-rules-2025",
"N-tanacetum-vulgare",
"S27",
"Fremont-list-definitions"
],
"description": "Common tansy: Toxic ingestion; contact dermatitis. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-tanacetum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "common-tansy-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-tanacetum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "common-tansy-2"
},
{
"label": "People",
"sources": [
"N-tanacetum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "common-tansy-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "common-tansy-4"
},
{
"label": "Other animals",
"sources": [
"N-tanacetum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "common-tansy-5"
},
{
"id": "common-tansy-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-tansy-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/common-tansy.md"
}
---
# Common tansy
*Tanacetum vulgare*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Toxic ingestion; contact dermatitis.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Common tansy is not tansy ragwort (Jacobaea vulgaris). Their chemical hazards and flower structures differ.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Close view of three yellow buttonlike tansy flower heads, showing tiny disk florets.
Photo: Agnes Monkelbaan; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Bloemen_van_Boerenwormkruid_(Tanacetum_vulgare)._17-08-2025._(actm.)_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/30/Bloemen_van_Boerenwormkruid_%28Tanacetum_vulgare%29._17-08-2025._%28actm.%29_01.jpg). Source-identified photograph with visual consistency check Flowers of Tansy ( Tanacetum vulgare ). Focus stack of 28 photos. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Flatbed photographic scan of a deeply divided, toothed tansy leaf with a millimeter scale.
Photo: Dmitry Makeev; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:2020_year._Herbarium._Tanacetum_vulgare._img-005.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/ce/2020_year._Herbarium._Tanacetum_vulgare._img-005.jpg). Source-identified photograph with visual consistency check Tanacetum vulgare. Leaf adaxial side. Herbarium of the city Elektrostal Moscow Oblast, 2020 year. Created by scanography. Collection D.Makeev. Scale 1 unit = 1 mm. These are original colors. Please do not make edit. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering stem** — An upright tansy stem with divided leaves and clusters of yellow buttonlike flowers.
Photo: Benjamin Zwittnig; [CC BY 2.5 si](https://creativecommons.org/licenses/by/2.5/si/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Tanacetum_vulgare_lg3.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2c/Tanacetum_vulgare_lg3.JPG). Source-identified photograph with visual consistency check Navadni vratič na Limbarski gori. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Fern-like leaves and flat clusters of yellow, button-like flowerheads without showy ray petals. [N-tanacetum-vulgare](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/)
## Plants & habitat
Seeds, rhizomes and root fragments build dense stands that displace other plants and degrade pastures. [N-tanacetum-vulgare](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/)
## People
Thujone can cause serious poisoning, including convulsions, and the plant can irritate skin. Avoid teas and home remedies. [N-tanacetum-vulgare](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Toxicity is reported for horses and cattle. Specialist grazing by other animals is not a general feeding recommendation. [N-tanacetum-vulgare](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-tanacetum-vulgare** — [tanacetum vulgare — Plant Toolbox](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-tansy) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Common tansy is not tansy ragwort (Jacobaea vulgaris). Their chemical hazards and flower structures differ.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| common-tansy-1 | Recognize | Species-specific | N-tanacetum-vulgare | No quantitative safe exposure established here. |
| common-tansy-2 | Plants & habitat | Species-specific | N-tanacetum-vulgare | No quantitative safe exposure established here. |
| common-tansy-3 | People | Species-specific | N-tanacetum-vulgare | No quantitative safe exposure established here. |
| common-tansy-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-tansy-5 | Other animals | Species-specific | N-tanacetum-vulgare | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/index.md
---
{
"id": "common-teasel",
"name": "Common teasel",
"scientific": "Dipsacus fullonum",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-teasel"
],
"warning": "Prickly heads; prolific seed spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "The Colorado county designation is for Dipsacus spp. This page illustrates source-identified D. fullonum; cutleaf teasel, D. laciniatus, requires a separate identification.",
"source_ids": [
"J-teasel",
"Fremont-list-definitions"
],
"description": "Common teasel: Prickly heads; prolific seed spread. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-teasel"
],
"scope": "Dipsacus group; source-identified photo examples",
"note": "",
"id": "common-teasel-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-teasel"
],
"scope": "Dipsacus group",
"note": "",
"id": "common-teasel-2"
},
{
"label": "People",
"sources": [
"J-teasel"
],
"scope": "Physical-risk inference",
"note": "",
"id": "common-teasel-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-teasel"
],
"scope": "Physical-risk inference; toxicity gap",
"note": "",
"id": "common-teasel-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "common-teasel-5"
},
{
"id": "common-teasel-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"common-teasel-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"common-teasel-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/common-teasel.md"
}
---
# Common teasel
*Dipsacus fullonum*
**Colorado noxious weed · List B — Stop the spread.** [J-teasel](https://www.jeffco.us/2152/Teasel)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Prickly heads; prolific seed spread.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The Colorado county designation is for Dipsacus spp. This page illustrates source-identified D. fullonum; cutleaf teasel, D. laciniatus, requires a separate identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Tall erect teasel stem with opposite leaves and branching upper flower-head stalks.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:DIPSACUS_FULLONUM_-_LLANERA_-_IB-822_(Card%C3%B3).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/3/31/DIPSACUS_FULLONUM_-_LLANERA_-_IB-822_%28Card%C3%B3%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common teasel is also recorded as Dipsacus sylvestris. Do not transfer the identification to cutleaf teasel (D. laciniatus) or cultivated fuller's teasel (D. sativus) without checking diagnostic features. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Egg-shaped prickly head with a horizontal band of lilac flowers and long curved basal bracts.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:DIPSACUS_FULLONUM_-_LLANERA_-_IB-083_(Card%C3%B3).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6f/DIPSACUS_FULLONUM_-_LLANERA_-_IB-083_%28Card%C3%B3%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common teasel is also recorded as Dipsacus sylvestris. Do not transfer the identification to cutleaf teasel (D. laciniatus) or cultivated fuller's teasel (D. sativus) without checking diagnostic features. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-stem** — Opposite leaves join around a prickly stem to form a water-holding cup.
Photo: Björn Appel; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Dipsacus-fullonum-water-storage.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/78/Dipsacus-fullonum-water-storage.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Common teasel is also recorded as Dipsacus sylvestris. Do not transfer the identification to cutleaf teasel (D. laciniatus) or cultivated fuller's teasel (D. sativus) without checking diagnostic features. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Prickly oval heads above stems with paired leaves that form cups. The county’s teasel account describes purple or white flowers and curved bracts. [J-teasel](https://www.jeffco.us/2152/Teasel)
*Evidence scope: Dipsacus group; source-identified photo examples.*
## Plants & habitat
Introduced teasels spread by seed in disturbed areas and ditch banks. Remove rosettes or flowering heads before seed dispersal and monitor for new plants. [J-teasel](https://www.jeffco.us/2152/Teasel)
*Evidence scope: Dipsacus group.*
## People
Prickly heads and stems present a handling hazard; gloves are a practical precaution. [J-teasel](https://www.jeffco.us/2152/Teasel)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Prickly dried material may injure paws or mouths. Chemical toxicity has not been established here. [J-teasel](https://www.jeffco.us/2152/Teasel)
*Evidence scope: Physical-risk inference; toxicity gap.*
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-teasel** — [Teasel](https://www.jeffco.us/2152/Teasel), Jefferson County, Colorado. Accessed 2026-09-07T00:27:26+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-teasel) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
The Colorado county designation is for Dipsacus spp. This page illustrates source-identified D. fullonum; cutleaf teasel, D. laciniatus, requires a separate identification.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| common-teasel-1 | Recognize | Dipsacus group; source-identified photo examples | J-teasel | No quantitative exposure threshold established here. |
| common-teasel-2 | Plants & habitat | Dipsacus group | J-teasel | No quantitative exposure threshold established here. |
| common-teasel-3 | People | Physical-risk inference | J-teasel | No quantitative exposure threshold established here. |
| common-teasel-4 | Dogs & cats | Physical-risk inference; toxicity gap | J-teasel | No quantitative exposure threshold established here. |
| common-teasel-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/index.md
---
{
"id": "common-yarrow",
"name": "Common yarrow",
"scientific": "Achillea millefolium",
"category": "xeriscape",
"status": "Low-water garden plant",
"status_sources": [
"S03",
"S07"
],
"warning": "Toxic to pets · Skin irritation",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S03",
"S07",
"S08"
],
"description": "Common yarrow: Toxic to pets · Skin irritation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S07"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-yarrow-1"
},
{
"label": "Plants & habitat",
"sources": [
"S07"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-yarrow-2"
},
{
"label": "People",
"sources": [
"S07"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-yarrow-3"
},
{
"label": "Dogs & cats",
"sources": [
"S08"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-yarrow-4"
},
{
"label": "Other animals",
"sources": [
"S08"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "common-yarrow-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/common-yarrow.md"
}
---
# Common yarrow
*Achillea millefolium*
**Low-water garden plant.** [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf) [S07](https://plants.ces.ncsu.edu/plants/achillea-millefolium/)
> **Toxic to pets · Skin irritation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — White flower-head cluster viewed from above, with individual ray and disk florets visible.
Photo: Petar Milošević; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Yarrow_(Achillea_millefolium).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/17/Yarrow_%28Achillea_millefolium%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Upright flowering yarrow stems with white flat-topped clusters growing among grasses.
Photo: Daniel VILLAFRUELA .; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Achillea_millefolium-Achill%C3%A9e_millefeuille-20190726.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2e/Achillea_millefolium-Achill%C3%A9e_millefeuille-20190726.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Finely divided, featherlike yarrow leaves along a hairy stem.
Photo: Alpsdake; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Achillea_millefolium_(leaf).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5b/Achillea_millefolium_%28leaf%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Finely divided, fernlike leaves and flat-topped clusters of small flowers. Native range includes North America, Europe, and Asia; cultivated forms vary. [S07](https://plants.ces.ncsu.edu/plants/achillea-millefolium/)
## Plants & habitat
Tolerates drought and feeds pollinators, but can spread aggressively through underground stems and seed. [S07](https://plants.ces.ncsu.edu/plants/achillea-millefolium/)
## People
Contact can cause dermatitis. Gloves reduce skin contact during garden work. [S07](https://plants.ces.ncsu.edu/plants/achillea-millefolium/)
## Dogs & cats
Toxic to dogs and cats. Reported signs include vomiting, diarrhea, drooling, and dermatitis. [S08](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow)
## Other animals
Also toxic to horses. ASPCA includes colic among reported signs; do not infer safety for other livestock. [S08](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S03** — [Low-Water Native Plants for Colorado Gardens: Front Range & Foothills](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf), Colorado Native Plant Society / CSU Extension. Accessed 2026-09-07T00:23:53+00:00. Locator: Plant table: Asclepias speciosa and Achillea millefolium.
- **S07** — [Achillea millefolium](https://plants.ces.ncsu.edu/plants/achillea-millefolium/), NC State Extension · Plant Toolbox. Accessed 2026-09-07T00:23:53+00:00. Locator: Description; Problems; Wildlife Value.
- **S08** — [Yarrow](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow), ASPCA Poison Control. Accessed 2026-09-07T00:23:53+00:00. Locator: Scientific Name; Toxicity; Clinical Signs.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=common-yarrow) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| common-yarrow-1 | Recognize | Species-specific | S07 | No quantitative exposure threshold established here. |
| common-yarrow-2 | Plants & habitat | Species-specific | S07 | No quantitative exposure threshold established here. |
| common-yarrow-3 | People | Species-specific | S07 | No quantitative exposure threshold established here. |
| common-yarrow-4 | Dogs & cats | Species-specific | S08 | No quantitative exposure threshold established here. |
| common-yarrow-5 | Other animals | Species-specific | S08 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/index.md
---
{
"id": "creeping-woodsorrel",
"name": "Creeping woodsorrel",
"scientific": "Oxalis corniculata",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Oxalate-containing plant; keep pets from grazing",
"warning_tone": "caution",
"aliases": [
"creeping wood sorrel",
"yellow oxalis"
],
"taxonomy_note": "Oxalis corniculata is not a Trifolium clover or a Rumex sorrel. Do not attach an ASPCA Rumex scutatus entry to this plant merely because both are called sorrel.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-oxalis-corniculata",
"S27"
],
"description": "Creeping woodsorrel: Oxalate-containing plant; keep pets from grazing. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Species-specific",
"note": "",
"id": "creeping-woodsorrel-1"
},
{
"label": "People",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Species-specific",
"note": "",
"id": "creeping-woodsorrel-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Species-specific",
"note": "",
"id": "creeping-woodsorrel-3"
},
{
"label": "Other animals",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Genus-level horse evidence",
"note": "",
"id": "creeping-woodsorrel-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Species-specific",
"note": "",
"id": "creeping-woodsorrel-5"
},
{
"label": "Management & timing",
"sources": [
"N-oxalis-corniculata"
],
"scope": "Species-specific",
"note": "",
"id": "creeping-woodsorrel-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 67; Oxalis corniculata",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Oxalis corniculata"
},
"source": "content/plants/creeping-woodsorrel.md"
}
---
# Creeping woodsorrel
*Oxalis corniculata*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Oxalate-containing plant; keep pets from grazing.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Oxalis corniculata is not a Trifolium clover or a Rumex sorrel. Do not attach an ASPCA Rumex scutatus entry to this plant merely because both are called sorrel.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A low leafy patch of creeping woodsorrel with small yellow flowers.
Photo: Forest & Kim Starr; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Starr_050404-5397_Oxalis_corniculata.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/67/Starr_050404-5397_Oxalis_corniculata.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified O. corniculata, including purple-leaved forms where shown. Related yellow-flowered Oxalis can resemble it; habit, stipules, hairs and fruits may be needed to identify an unknown specimen. No cultivar determination is made. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower** — A yellow five-petaled flower with fine reddish veins near the center.
Photo: André Karwath aka Aka; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Oxalis_corniculata_-_blossom_top_(aka).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/25/Oxalis_corniculata_-_blossom_top_%28aka%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified O. corniculata, including purple-leaved forms where shown. Related yellow-flowered Oxalis can resemble it; habit, stipules, hairs and fruits may be needed to identify an unknown specimen. No cultivar determination is made. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruit** — An elongated pointed green capsule with fine surface hairs on a curved stalk, photographed with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Oxalis_corniculata_sl12.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/9d/Oxalis_corniculata_sl12.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified O. corniculata, including purple-leaved forms where shown. Related yellow-flowered Oxalis can resemble it; habit, stipules, hairs and fruits may be needed to identify an unknown specimen. No cultivar determination is made. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
Three heart-shaped leaflets can resemble clover, but the flowers are yellow and seed capsules are narrow and cylindrical. Creeping stems spread across the ground. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
## People
All parts have toxic potential from soluble oxalates. A sour taste or a reference to traditional food use is not a safe-amount recommendation. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
## Dogs & cats
NC State flags this species as a problem for dogs and cats. Prevent repeated grazing; the reviewed entry does not quantify a safe amount or species-specific clinical outcome in pets. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
## Other animals
The source reports colic and possible kidney injury after substantial ingestion of Oxalis by horses. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
*Evidence scope: Genus-level horse evidence.*
## Plants & habitat
Ripe capsules eject seeds, and spreading stems can make established patches difficult to remove. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
## Management & timing
Inspect incoming nursery plants and remove volunteers before capsules mature. Recheck for regrowth and seedlings. [N-oxalis-corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-oxalis-corniculata** — [Oxalis corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=creeping-woodsorrel) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 67; Oxalis corniculata. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Oxalis corniculata is not a Trifolium clover or a Rumex sorrel. Do not attach an ASPCA Rumex scutatus entry to this plant merely because both are called sorrel.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| creeping-woodsorrel-1 | Identification | Species-specific | N-oxalis-corniculata | No quantitative safe exposure established here. |
| creeping-woodsorrel-2 | People | Species-specific | N-oxalis-corniculata | No quantitative safe exposure established here. |
| creeping-woodsorrel-3 | Dogs & cats | Species-specific | N-oxalis-corniculata | No quantitative safe exposure established here. |
| creeping-woodsorrel-4 | Other animals | Genus-level horse evidence | N-oxalis-corniculata | No quantitative safe exposure established here. |
| creeping-woodsorrel-5 | Plants & habitat | Species-specific | N-oxalis-corniculata | No quantitative safe exposure established here. |
| creeping-woodsorrel-6 | Management & timing | Species-specific | N-oxalis-corniculata | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md
---
{
"id": "crownvetch",
"name": "Crownvetch",
"scientific": "Securigera varia",
"category": "invasive",
"status": "Introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Toxic to horses; spreading roots can smother vegetation",
"warning_tone": "danger",
"aliases": [
"Coronilla varia",
"crown vetch",
"purple crownvetch"
],
"taxonomy_note": "Older NC State material uses Coronilla varia; the Colorado assessment uses Securigera varia. This is separate from Vicia species and their distinct feeding hazards.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-securigera-varia",
"F-securigera",
"S27"
],
"description": "Crownvetch: Toxic to horses; spreading roots can smother vegetation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-securigera-varia",
"F-securigera"
],
"scope": "Species-specific",
"note": "",
"id": "crownvetch-1"
},
{
"label": "People",
"sources": [
"N-securigera-varia"
],
"scope": "Species-specific",
"note": "",
"id": "crownvetch-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-securigera-varia",
"F-securigera"
],
"scope": "Animal-group evidence; pet-specific gap",
"note": "",
"id": "crownvetch-3"
},
{
"label": "Other animals",
"sources": [
"F-securigera"
],
"scope": "Species-specific",
"note": "",
"id": "crownvetch-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-securigera-varia"
],
"scope": "Species-specific",
"note": "",
"id": "crownvetch-5"
},
{
"label": "Management & timing",
"sources": [
"N-securigera-varia",
"F-securigera"
],
"scope": "Management synthesis",
"note": "",
"id": "crownvetch-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"crownvetch-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 79; Securigera varia",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Securigera varia"
},
"source": "content/plants/crownvetch.md"
}
---
# Crownvetch
*Securigera varia*
**Introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Toxic to horses; spreading roots can smother vegetation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Older NC State material uses Coronilla varia; the Colorado assessment uses Securigera varia. This is separate from Vicia species and their distinct feeding hazards.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Sprawling crownvetch stems with many pink-and-white flower clusters and pinnate leaves among other vegetation.
Photo: Dale Knox; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/51529919); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/81878677/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers** — Pink-and-white crownvetch flowers grouped in a rounded cluster beside a compound leaf.
Photo: Eleftherios Katsillis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/65160254); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/104834388/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves** — Arching crownvetch leaves with numerous paired oval leaflets and a terminal leaflet, seen against the sky.
Photo: Eleftherios Katsillis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/65160254); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/104834426/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A trailing perennial legume with many paired leaflets and rounded clusters of pink-and-white pea flowers. Unlike true vetches, it lacks tendrils. [N-securigera-varia](https://plants.ces.ncsu.edu/plants/securigera-varia/) [F-securigera](https://research.fs.usda.gov/feis/species-reviews/secvar)
## People
NC State lists poisonous characteristics and potentially serious ingestion effects. No safe amount is established. [N-securigera-varia](https://plants.ces.ncsu.edu/plants/securigera-varia/)
## Dogs & cats
Sources warn about nonruminants, but reviewed species-specific dog and cat clinical evidence is incomplete. Prevent chewing; cattle forage use cannot be treated as pet clearance. [N-securigera-varia](https://plants.ces.ncsu.edu/plants/securigera-varia/) [F-securigera](https://research.fs.usda.gov/feis/species-reviews/secvar)
*Evidence scope: Animal-group evidence; pet-specific gap.*
## Other animals
Crownvetch contains nitroglycosides toxic to horses. Its use as forage for some ruminants does not make it suitable horse feed. [F-securigera](https://research.fs.usda.gov/feis/species-reviews/secvar)
## Plants & habitat
It spreads by rhizomes and seed and can form a dense cover that displaces other plants. Former erosion-control use explains many naturalized colonies. [N-securigera-varia](https://plants.ces.ncsu.edu/plants/securigera-varia/)
## Management & timing
Avoid introducing it near natural habitat or horse forage. Established root systems need a sustained local control plan and monitoring. [N-securigera-varia](https://plants.ces.ncsu.edu/plants/securigera-varia/) [F-securigera](https://research.fs.usda.gov/feis/species-reviews/secvar)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-securigera-varia** — [Securigera varia](https://plants.ces.ncsu.edu/plants/securigera-varia/), NC State Extension. Accessed 2026-09-07T02:23:14+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **F-securigera** — [Crownvetch](https://research.fs.usda.gov/feis/species-reviews/secvar), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:26:13+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=crownvetch) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 79; Securigera varia. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Older NC State material uses Coronilla varia; the Colorado assessment uses Securigera varia. This is separate from Vicia species and their distinct feeding hazards.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| crownvetch-1 | Identification | Species-specific | N-securigera-varia, F-securigera | No quantitative safe exposure established here. |
| crownvetch-2 | People | Species-specific | N-securigera-varia | No quantitative safe exposure established here. |
| crownvetch-3 | Dogs & cats | Animal-group evidence; pet-specific gap | N-securigera-varia, F-securigera | No quantitative safe exposure established here. |
| crownvetch-4 | Other animals | Species-specific | F-securigera | No quantitative safe exposure established here. |
| crownvetch-5 | Plants & habitat | Species-specific | N-securigera-varia | No quantitative safe exposure established here. |
| crownvetch-6 | Management & timing | Management synthesis | N-securigera-varia, F-securigera | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/index.md
---
{
"id": "curly-dock",
"name": "Curly dock",
"scientific": "Rumex crispus",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Soluble oxalates; persistent roots and seeds",
"warning_tone": "caution",
"aliases": [
"yellow dock"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-rumex-crispus",
"C-descriptions",
"S27"
],
"description": "Curly dock: Soluble oxalates; persistent roots and seeds. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-rumex-crispus"
],
"scope": "Species-specific",
"note": "",
"id": "curly-dock-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions",
"N-rumex-crispus"
],
"scope": "Species-specific",
"note": "",
"id": "curly-dock-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "curly-dock-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-rumex-crispus"
],
"scope": "Species-specific",
"note": "",
"id": "curly-dock-4"
},
{
"label": "Other animals",
"sources": [
"N-rumex-crispus"
],
"scope": "Source hazard flag; limited horse clinical detail",
"note": "",
"id": "curly-dock-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"curly-dock-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"curly-dock-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/curly-dock.md"
}
---
# Curly dock
*Rumex crispus*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Soluble oxalates; persistent roots and seeds.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruiting habit** — A broad, branching fruiting plant in open disturbed ground.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Rumex_crispus_15-p.bot-rumex.crispu-19.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0b/Rumex_crispus_15-p.bot-rumex.crispu-19.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Dock species and hybrids can overlap. Source identification is retained; the selected fruit view shows a valve and tubercle, while leaf shape alone is insufficient. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf edge** — Magnified view of a leaf surface and wavy margin.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/172492542); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/299454892/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Dock species and hybrids can overlap. Source identification is retained; the selected fruit view shows a valve and tubercle, while leaf shape alone is insufficient. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit detail** — A dry fruiting unit held with forceps, showing a papery net-veined valve and a prominent central tubercle.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/172492542); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/299454085/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Dock species and hybrids can overlap. Source identification is retained; the selected fruit view shows a valve and tubercle, while leaf shape alone is insufficient. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A basal rosette and upright stems with long, wavy-edged leaves; green flower clusters mature to brown seed structures. [N-rumex-crispus](https://plants.ces.ncsu.edu/plants/rumex-crispus/)
## Plants & habitat
A Colorado weed of disturbed land. Its long-lived root and persistent seeds allow survival through mowing and changing moisture. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-rumex-crispus](https://plants.ces.ncsu.edu/plants/rumex-crispus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
NC State flags dogs and cats and reports soluble oxalates, salivation, tremors and possible kidney injury; it describes kidney failure as rare in these pets. [N-rumex-crispus](https://plants.ces.ncsu.edu/plants/rumex-crispus/)
## Other animals
The source flags horses, but does not establish a safe forage quantity. [N-rumex-crispus](https://plants.ces.ncsu.edu/plants/rumex-crispus/)
*Evidence scope: Source hazard flag; limited horse clinical detail.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-rumex-crispus** — [rumex crispus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/rumex-crispus/), NC State Extension. Accessed 2026-09-07T01:21:11+00:00. Locator: Species identity, description, ecology, toxicity.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=curly-dock) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| curly-dock-1 | Recognize | Species-specific | N-rumex-crispus | No quantitative safe exposure established here. |
| curly-dock-2 | Plants & habitat | Species-specific | C-descriptions, N-rumex-crispus | No quantitative safe exposure established here. |
| curly-dock-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| curly-dock-4 | Dogs & cats | Species-specific | N-rumex-crispus | No quantitative safe exposure established here. |
| curly-dock-5 | Other animals | Source hazard flag; limited horse clinical detail | N-rumex-crispus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/index.md
---
{
"id": "curlycup-gumweed",
"name": "Curlycup gumweed",
"scientific": "Grindelia squarrosa",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Sticky resin and conditional selenium concern",
"warning_tone": "caution",
"aliases": [
"gumweed",
"resinweed"
],
"taxonomy_note": "Grindelia squarrosa includes multiple varieties. Photographs and this profile do not constitute a variety-level key or a selenium test.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-grindelia",
"S27"
],
"description": "Curlycup gumweed: Sticky resin and conditional selenium concern. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-grindelia"
],
"scope": "Species-specific",
"note": "",
"id": "curlycup-gumweed-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "curlycup-gumweed-2"
},
{
"label": "Dogs & cats",
"sources": [
"F-grindelia"
],
"scope": "Contact precaution inferred from livestock observations",
"note": "",
"id": "curlycup-gumweed-3"
},
{
"label": "Other animals",
"sources": [
"F-grindelia"
],
"scope": "Species-specific",
"note": "",
"id": "curlycup-gumweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-grindelia"
],
"scope": "Species-specific",
"note": "",
"id": "curlycup-gumweed-5"
},
{
"label": "Management & timing",
"sources": [
"F-grindelia",
"S27"
],
"scope": "Management synthesis",
"note": "",
"id": "curlycup-gumweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"curlycup-gumweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"curlycup-gumweed-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 56; Grindelia squarrosa",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Grindelia squarrosa"
},
"source": "content/plants/curlycup-gumweed.md"
}
---
# Curlycup gumweed
*Grindelia squarrosa*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Sticky resin and conditional selenium concern.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Grindelia squarrosa includes multiple varieties. Photographs and this profile do not constitute a variety-level key or a selenium test.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Rounded, densely branching curlycup gumweed plant covered with yellow flower heads.
Photo: Jesse Grove; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/131957641); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/224643870/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower** — Side view of a yellow curlycup gumweed flower head with green, outward-curving bracts below it.
Photo: Zach Earl; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/249666100); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/446344737/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**buds-leaves** — Curlycup gumweed buds with spreading green bracts beside toothed leaves on a reddish stem.
Photo: Jared Shorma; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/55340556); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/88114065/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A branching, taprooted biennial or perennial with resinous foliage and flower heads. Growth form varies among the varieties grouped in this species. [F-grindelia](https://research.fs.usda.gov/feis/species-reviews/grisqu)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
Sticky secretions are a practical grooming concern, inferred from reports of livestock coats becoming gummed. Pet ingestion toxicity is unresolved. [F-grindelia](https://research.fs.usda.gov/feis/species-reviews/grisqu)
*Evidence scope: Contact precaution inferred from livestock observations.*
## Other animals
Usually unpalatable to livestock. Resin can gum coats, and the plant can absorb selenium when it is available; this does not mean every specimen contains a toxic concentration. [F-grindelia](https://research.fs.usda.gov/feis/species-reviews/grisqu)
## Plants & habitat
It tolerates dry disturbed ground and may form dense patches on depleted range or roadsides. Native status and weediness depend on context. [F-grindelia](https://research.fs.usda.gov/feis/species-reviews/grisqu)
## Management & timing
Investigate site condition before broad removal. For an unwanted small patch, prevent seed production and monitor replacement vegetation. [F-grindelia](https://research.fs.usda.gov/feis/species-reviews/grisqu) [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-grindelia** — [Curlycup gumweed](https://research.fs.usda.gov/feis/species-reviews/grisqu), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=curlycup-gumweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 56; Grindelia squarrosa. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Grindelia squarrosa includes multiple varieties. Photographs and this profile do not constitute a variety-level key or a selenium test.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| curlycup-gumweed-1 | Identification | Species-specific | F-grindelia | No quantitative safe exposure established here. |
| curlycup-gumweed-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| curlycup-gumweed-3 | Dogs & cats | Contact precaution inferred from livestock observations | F-grindelia | No quantitative safe exposure established here. |
| curlycup-gumweed-4 | Other animals | Species-specific | F-grindelia | No quantitative safe exposure established here. |
| curlycup-gumweed-5 | Plants & habitat | Species-specific | F-grindelia | No quantitative safe exposure established here. |
| curlycup-gumweed-6 | Management & timing | Management synthesis | F-grindelia, S27 | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/index.md
---
{
"id": "cutleaf-teasel",
"name": "Cutleaf teasel",
"scientific": "Dipsacus laciniatus",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Prickly stands can displace native vegetation",
"warning_tone": "caution",
"aliases": [
"cut-leaved teasel"
],
"taxonomy_note": "Common teasel usually has unlobed leaves and lavender flowers. Flower color alone does not establish the species.",
"source_ids": [
"CO-rules-2025",
"F-teasels",
"S27",
"Fremont-list-definitions"
],
"description": "Cutleaf teasel: Prickly stands can displace native vegetation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-teasels"
],
"scope": "Species-specific",
"note": "",
"id": "cutleaf-teasel-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-teasels"
],
"scope": "Species-specific",
"note": "",
"id": "cutleaf-teasel-2"
},
{
"label": "People",
"sources": [
"F-teasels"
],
"scope": "Physical-risk inference",
"note": "",
"id": "cutleaf-teasel-3"
},
{
"label": "Dogs & cats",
"sources": [
"F-teasels"
],
"scope": "Physical-risk inference; ingestion evidence gap",
"note": "",
"id": "cutleaf-teasel-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "cutleaf-teasel-5"
},
{
"id": "cutleaf-teasel-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"cutleaf-teasel-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"cutleaf-teasel-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/cutleaf-teasel.md"
}
---
# Cutleaf teasel
*Dipsacus laciniatus*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Prickly stands can displace native vegetation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Common teasel usually has unlobed leaves and lavender flowers. Flower color alone does not establish the species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**dry head** — Dry oval teasel head on a prickly stalk, with rigid bracts surrounding the head.
Photo: Alexander Klink; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Dipsacus_laciniatus_L.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/40/Dipsacus_laciniatus_L.jpg). Source-identified photograph with visual consistency check Dipsacus laciniatus L. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaves and stem** — Opposite, deeply cut leaves around a teasel stem, with an oval flowering head behind them.
Photo: Alex Abair; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Dipsacus_laciniatus_554862782.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fb/Dipsacus_laciniatus_554862782.jpg). Source-identified photograph with visual consistency check Cutleaf teasel ( Dipsacus laciniatus ) in the United States Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Close view of small white flowers on an oval teasel head among pointed bracts, with a 20 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Dipsacus_laciniatus_sl21.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7b/Dipsacus_laciniatus_sl21.jpg). Source-identified photograph with visual consistency check Capitulum (detail) Taxonym: Dipsacus laciniatus ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Marchfeldkanal near Groß-Jedlersdorf, Wien-Floridsdorf - ca. 160 m a.s.l. Habitat: fallow land Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Deeply cut, opposite leaves clasp the stem; generally white flowers open on prickly, elongated heads. [F-teasels](https://research.fs.usda.gov/feis/species-reviews/dipspp)
## Plants & habitat
Reported near Denver. Dense stands can threaten meadow and wetland vegetation; impacts vary among sites. [F-teasels](https://research.fs.usda.gov/feis/species-reviews/dipspp)
## People
Prickles on stems and heads make unprotected handling a puncture concern. [F-teasels](https://research.fs.usda.gov/feis/species-reviews/dipspp)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Prickly plants present a contact hazard; the reviewed source does not establish pet ingestion effects. [F-teasels](https://research.fs.usda.gov/feis/species-reviews/dipspp)
*Evidence scope: Physical-risk inference; ingestion evidence gap.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-teasels** — [Fuller’s and cutleaf teasel](https://research.fs.usda.gov/feis/species-reviews/dipspp), USDA Forest Service. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=cutleaf-teasel) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Common teasel usually has unlobed leaves and lavender flowers. Flower color alone does not establish the species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| cutleaf-teasel-1 | Recognize | Species-specific | F-teasels | No quantitative safe exposure established here. |
| cutleaf-teasel-2 | Plants & habitat | Species-specific | F-teasels | No quantitative safe exposure established here. |
| cutleaf-teasel-3 | People | Physical-risk inference | F-teasels | No quantitative safe exposure established here. |
| cutleaf-teasel-4 | Dogs & cats | Physical-risk inference; ingestion evidence gap | F-teasels | No quantitative safe exposure established here. |
| cutleaf-teasel-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md
---
{
"id": "cypress-spurge",
"name": "Cypress spurge",
"scientific": "Euphorbia cyparissias",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Sap can injure skin and eyes",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-euphorbia-cyparissias",
"S27",
"Fremont-list-definitions"
],
"description": "Cypress spurge: Sap can injure skin and eyes. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-euphorbia-cyparissias"
],
"scope": "Species-specific",
"note": "",
"id": "cypress-spurge-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-euphorbia-cyparissias"
],
"scope": "Species-specific",
"note": "",
"id": "cypress-spurge-2"
},
{
"label": "People",
"sources": [
"N-euphorbia-cyparissias"
],
"scope": "Species-specific",
"note": "",
"id": "cypress-spurge-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-euphorbia-cyparissias"
],
"scope": "Species-specific",
"note": "",
"id": "cypress-spurge-4"
},
{
"label": "Other animals",
"sources": [
"N-euphorbia-cyparissias"
],
"scope": "Species-specific",
"note": "",
"id": "cypress-spurge-5"
},
{
"id": "cypress-spurge-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/cypress-spurge.md"
}
---
# Cypress spurge
*Euphorbia cyparissias*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sap can injure skin and eyes.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Yellow-green floral bracts and small cyathia above many narrow leaves.
Photo: Tom Scavo; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/287543772); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/517027187/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage** — A shoot held to show its closely spaced, narrow linear leaves.
Photo: Tom Scavo; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/287543772); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/517027195/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Several low flowering shoots growing in a rocky crevice.
Photo: Tom Scavo; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/287543772); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/517027581/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A low perennial with crowded, needle-like leaves and yellow-green flower bracts. Do not snap stems to test for milky sap. [N-euphorbia-cyparissias](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/)
## Plants & habitat
Rhizomes and seed build dense colonies that can overrun neighboring vegetation. [N-euphorbia-cyparissias](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/)
## People
Latex can cause dermatitis, mouth injury and serious corneal damage. Protect skin and eyes during handling. [N-euphorbia-cyparissias](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/)
## Dogs & cats
NC State flags dogs and cats and advises keeping pets away. This is not a pet-specific dose assessment. [N-euphorbia-cyparissias](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/)
## Other animals
The source reports potential toxicity to cattle and horses. [N-euphorbia-cyparissias](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-euphorbia-cyparissias** — [euphorbia cyparissias — Plant Toolbox](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=cypress-spurge) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| cypress-spurge-1 | Recognize | Species-specific | N-euphorbia-cyparissias | No quantitative safe exposure established here. |
| cypress-spurge-2 | Plants & habitat | Species-specific | N-euphorbia-cyparissias | No quantitative safe exposure established here. |
| cypress-spurge-3 | People | Species-specific | N-euphorbia-cyparissias | No quantitative safe exposure established here. |
| cypress-spurge-4 | Dogs & cats | Species-specific | N-euphorbia-cyparissias | No quantitative safe exposure established here. |
| cypress-spurge-5 | Other animals | Species-specific | N-euphorbia-cyparissias | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/index.md
---
{
"id": "dalmatian-toadflax",
"name": "Dalmatian toadflax",
"scientific": "Linaria dalmatica",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-dalmatian-toadflax"
],
"warning": "Spreads from roots; livestock concern",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.",
"source_ids": [
"J-dalmatian-toadflax",
"Fremont-list-definitions"
],
"description": "Dalmatian toadflax: Spreads from roots; livestock concern. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-dalmatian-toadflax"
],
"scope": "Species-specific",
"note": "",
"id": "dalmatian-toadflax-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-dalmatian-toadflax"
],
"scope": "Species-specific",
"note": "",
"id": "dalmatian-toadflax-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human ingestion effects were not established in this review.",
"id": "dalmatian-toadflax-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "dalmatian-toadflax-4"
},
{
"label": "Other animals",
"sources": [
"J-dalmatian-toadflax"
],
"scope": "Possible livestock toxicity; pet evidence gap",
"note": "",
"id": "dalmatian-toadflax-5"
},
{
"id": "dalmatian-toadflax-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"dalmatian-toadflax-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"dalmatian-toadflax-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"dalmatian-toadflax-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/dalmatian-toadflax.md"
}
---
# Dalmatian toadflax
*Linaria dalmatica*
**Colorado noxious weed · List B — Stop the spread.** [J-dalmatian-toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spreads from roots; livestock concern.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flowering-stem** — Erect stem bearing a long series of yellow flowers and broad clasping leaves.
Photo: Walter Siegmund (talk); [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Linaria_dalmatica_0562.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6e/Linaria_dalmatica_0562.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Yellow snapdragon-shaped flowers with long narrow spurs.
Photo: milan_chytry; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Balkan_Toadflax_(Linaria_dalmatica),_Bra%C8%99ov,_Romania_1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/de/Balkan_Toadflax_%28Linaria_dalmatica%29%2C_Bra%C8%99ov%2C_Romania_1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Broad blue-green leaves clasp the upright stem at their bases.
Photo: viridian; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Balkan_Toadflax_(Linaria_dalmatica),_Brela,_Croatia_2.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/37/Balkan_Toadflax_%28Linaria_dalmatica%29%2C_Brela%2C_Croatia_2.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow snapdragon-like flowers with long spurs; broad, waxy, heart-shaped leaves clasp the stems. [J-dalmatian-toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax)
## Plants & habitat
A perennial spreading by roots and seed. Root fragments can form new plants; repeated casual digging or mowing is unlikely to solve an established patch. [J-dalmatian-toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax)
## People
Human ingestion effects were not established in this review. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
The county reports possible livestock toxicity. Grazing is not recommended as a simple control method; pet safety cannot be inferred from this warning. [J-dalmatian-toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-dalmatian-toadflax** — [Dalmatian Toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax), Jefferson County, Colorado. Accessed 2026-09-07T00:27:22+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=dalmatian-toadflax) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| dalmatian-toadflax-1 | Recognize | Species-specific | J-dalmatian-toadflax | No quantitative exposure threshold established here. |
| dalmatian-toadflax-2 | Plants & habitat | Species-specific | J-dalmatian-toadflax | No quantitative exposure threshold established here. |
| dalmatian-toadflax-3 | People | Review limitation | Review limitation | Human ingestion effects were not established in this review. |
| dalmatian-toadflax-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| dalmatian-toadflax-5 | Other animals | Possible livestock toxicity; pet evidence gap | J-dalmatian-toadflax | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/index.md
---
{
"id": "dames-rocket",
"name": "Dame’s rocket",
"scientific": "Hesperis matronalis",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-dames-rocket"
],
"warning": "Escapes gardens and spreads",
"warning_tone": "caution",
"aliases": [
"dame's rocket"
],
"taxonomy_note": "Four petals help distinguish this mustard relative from five-petaled garden phlox; this clue alone is not a complete identification.",
"source_ids": [
"J-dames-rocket",
"C-descriptions",
"Fremont-list-definitions"
],
"description": "Dame’s rocket: Escapes gardens and spreads. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "dames-rocket-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "dames-rocket-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed sources do not establish ingestion safety.",
"id": "dames-rocket-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "dames-rocket-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "dames-rocket-5"
},
{
"id": "dames-rocket-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"dames-rocket-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"dames-rocket-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"dames-rocket-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/dames-rocket.md"
}
---
# Dame’s rocket
*Hesperis matronalis*
**Colorado noxious weed · List B — Stop the spread.** [J-dames-rocket](https://www.jeffco.us/2467/Dames-Rocket)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Escapes gardens and spreads.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Four petals help distinguish this mustard relative from five-petaled garden phlox; this clue alone is not a complete identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Upright stems with alternate lance-shaped leaves and branching clusters of lilac flowers.
Photo: Anneli Salo; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Hesperis_matronalis_Illakko_VI08_H4934.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/9d/Hesperis_matronalis_Illakko_VI08_H4934.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Pink-purple flowers with four petals beside broad toothed leaves.
Photo: Algirdas at Lithuanian Wikipedia; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Hesperis_matronalis.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/3/32/Hesperis_matronalis.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**rosette** — Basal rosette of green leaves growing close to the soil surface.
Photo: User:SB_Johnny; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Hesperis_matronalis_basal_whorl_001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a2/Hesperis_matronalis_basal_whorl_001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Fragrant purple, pink or white flowers with four petals; often a biennial or short-lived perennial. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Plants & habitat
Introduced as an ornamental and can spread aggressively. Do not use seed mixes containing it; prevent seed set and follow up on seedlings. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## People
The reviewed sources do not establish ingestion safety. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-dames-rocket** — [Dames Rocket](https://www.jeffco.us/2467/Dames-Rocket), Jefferson County, Colorado. Accessed 2026-09-07T00:27:22+00:00. Locator: Description, impacts, Colorado list designation, management.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=dames-rocket) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Four petals help distinguish this mustard relative from five-petaled garden phlox; this clue alone is not a complete identification.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| dames-rocket-1 | Recognize | Species-specific | C-descriptions | No quantitative exposure threshold established here. |
| dames-rocket-2 | Plants & habitat | Species-specific | C-descriptions | No quantitative exposure threshold established here. |
| dames-rocket-3 | People | Review limitation | Review limitation | The reviewed sources do not establish ingestion safety. |
| dames-rocket-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| dames-rocket-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/index.md
---
{
"id": "diffuse-knapweed",
"name": "Diffuse knapweed",
"scientific": "Centaurea diffusa",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Skin irritation; tumbling seed spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Spotted knapweed and spotted × diffuse hybrids require separate identification. Russian-knapweed horse poisoning must not be transferred merely because the common names overlap.",
"source_ids": [
"CO-rules-2025",
"J-diffuse-knapweed",
"S27",
"Fremont-list-definitions"
],
"description": "Diffuse knapweed: Skin irritation; tumbling seed spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-diffuse-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "diffuse-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-diffuse-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "diffuse-knapweed-2"
},
{
"label": "People",
"sources": [
"J-diffuse-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "diffuse-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-diffuse-knapweed"
],
"scope": "Physical-risk inference; chemical-toxicity gap",
"note": "",
"id": "diffuse-knapweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "diffuse-knapweed-5"
},
{
"id": "diffuse-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"diffuse-knapweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"diffuse-knapweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/diffuse-knapweed.md"
}
---
# Diffuse knapweed
*Centaurea diffusa*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Skin irritation; tumbling seed spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Spotted knapweed and spotted × diffuse hybrids require separate identification. Russian-knapweed horse poisoning must not be transferred merely because the common names overlap.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Dense, widely branched diffuse knapweed bearing many small pale flower heads; photographed at Williams Fork Reservoir, Colorado.
Photo: Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_diffusa_kz06.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/87/Centaurea_diffusa_kz06.jpg). Source-identified photograph with visual consistency check Centaurea diffusa at Williams Fork Reservoir, Colorado, USA Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**heads and bracts** — Branching stems carrying small knapweed heads with pale spiny bracts.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_diffusa_sl40.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5e/Centaurea_diffusa_sl40.jpg). Source-identified photograph with visual consistency check Inflorescence with capitula Taxonym: Centaurea diffusa ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Kühberg east of Wieselsfeld next to Hollabrunn, district Hollabrunn, Lower Austria - ca. 325 m a.s.l. Habitat: fallow land Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**achenes** — Two pale knapweed achenes with short bristles, shown at close range with a 3 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_diffusa_sl12.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/25/Centaurea_diffusa_sl12.jpg). Source-identified photograph with visual consistency check Achenes with short pappus Taxonym: Centaurea diffusa ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: sand pit 0,4 south-eastern of Schleinbach, district Mistelbach, Lower Austria - ca. 270 m a.s.l. Habitat: extraction face of a sand pit Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Much-branched stems carry small white to pale purple flowerheads with long terminal spines on their bracts. [J-diffuse-knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed)
## Plants & habitat
Dry plants break off and tumble, spreading seeds through disturbed rangeland and roadsides. [J-diffuse-knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed)
## People
The county reports skin irritation. Wear gloves when handling plants. [J-diffuse-knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed)
## Dogs & cats
Spiny bracts present a physical contact concern. The reviewed source does not establish pet ingestion effects. [J-diffuse-knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed)
*Evidence scope: Physical-risk inference; chemical-toxicity gap.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-diffuse-knapweed** — [Diffuse Knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed), Jefferson County, Colorado. Accessed 2026-09-07T00:27:22+00:00. Locator: Description, impacts, Colorado list designation, management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=diffuse-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Spotted knapweed and spotted × diffuse hybrids require separate identification. Russian-knapweed horse poisoning must not be transferred merely because the common names overlap.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| diffuse-knapweed-1 | Recognize | Species-specific | J-diffuse-knapweed | No quantitative safe exposure established here. |
| diffuse-knapweed-2 | Plants & habitat | Species-specific | J-diffuse-knapweed | No quantitative safe exposure established here. |
| diffuse-knapweed-3 | People | Species-specific | J-diffuse-knapweed | No quantitative safe exposure established here. |
| diffuse-knapweed-4 | Dogs & cats | Physical-risk inference; chemical-toxicity gap | J-diffuse-knapweed | No quantitative safe exposure established here. |
| diffuse-knapweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/index.md
---
{
"id": "dyers-woad",
"name": "Dyer’s woad",
"scientific": "Isatis tinctoria",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Persistent seed spread",
"warning_tone": "caution",
"aliases": [
"dyer's woad"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-isatis-tinctoria",
"S27",
"Fremont-list-definitions"
],
"description": "Dyer’s woad: Persistent seed spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-isatis-tinctoria"
],
"scope": "Species-specific",
"note": "",
"id": "dyers-woad-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-isatis-tinctoria"
],
"scope": "Species-specific",
"note": "",
"id": "dyers-woad-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "dyers-woad-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "dyers-woad-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "dyers-woad-5"
},
{
"id": "dyers-woad-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"dyers-woad-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"dyers-woad-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"dyers-woad-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/dyers-woad.md"
}
---
# Dyer’s woad
*Isatis tinctoria*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Persistent seed spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering clusters** — Branched clusters of small yellow flowers above blue-green foliage.
Photo: Reuven Martin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/13222215); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/19337538/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of small four-petalled yellow flowers and unopened buds.
Photo: Reuven Martin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/13222215); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/19338209/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — An entire flowering stem with lower foliage growing from a stony surface.
Photo: aroche; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/9381472); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/12742971/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Blue-green rosette leaves precede branched stalks of four-petaled yellow flowers. Mature seed pods become dark and pendant. [N-isatis-tinctoria](https://plants.ces.ncsu.edu/plants/isatis-tinctoria/)
## Plants & habitat
A drought-tolerant introduced weed that reproduces from seed. Preventing seed production matters; ornamental dye use does not change its Colorado designation. [N-isatis-tinctoria](https://plants.ces.ncsu.edu/plants/isatis-tinctoria/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-isatis-tinctoria** — [isatis tinctoria — Plant Toolbox](https://plants.ces.ncsu.edu/plants/isatis-tinctoria/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=dyers-woad) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| dyers-woad-1 | Recognize | Species-specific | N-isatis-tinctoria | No quantitative safe exposure established here. |
| dyers-woad-2 | Plants & habitat | Species-specific | N-isatis-tinctoria | No quantitative safe exposure established here. |
| dyers-woad-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| dyers-woad-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| dyers-woad-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/index.md
---
{
"id": "elongated-mustard",
"name": "Elongated mustard",
"scientific": "Brassica elongata",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Early detection priority in dry disturbed land",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Reference photographs identify B. elongata subsp. integrifolia. Colorado lists B. elongata broadly. The fact sheet’s inconsistent sepal-count caption is not adopted.",
"source_ids": [
"CO-rules-2025",
"CO-elongated-mustard",
"S27",
"Fremont-list-definitions"
],
"description": "Elongated mustard: Early detection priority in dry disturbed land. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"CO-elongated-mustard"
],
"scope": "Species-specific",
"note": "",
"id": "elongated-mustard-1"
},
{
"label": "Plants & habitat",
"sources": [
"CO-elongated-mustard"
],
"scope": "Species-specific",
"note": "",
"id": "elongated-mustard-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "elongated-mustard-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "elongated-mustard-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "elongated-mustard-5"
},
{
"id": "elongated-mustard-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"elongated-mustard-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"elongated-mustard-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"elongated-mustard-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/elongated-mustard.md"
}
---
# Elongated mustard
*Brassica elongata*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Early detection priority in dry disturbed land.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Reference photographs identify B. elongata subsp. integrifolia. Colorado lists B. elongata broadly. The fact sheet’s inconsistent sepal-count caption is not adopted.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering stem** — A branched stem with yellow flowers growing beside paving.
Photo: Dmitriy Bochkov; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/123682558); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/209553087/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**lower foliage** — Lower leaves and the base of a sprawling stem beside a wall and path.
Photo: Dmitriy Bochkov; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/123682558); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/209553236/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — The flowering plant viewed from above, showing its branching pattern and lower leaves.
Photo: Dmitriy Bochkov; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/123682558); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/209553302/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observation is identified more narrowly as Brassica elongata integrifolia. That source name is preserved rather than silently relabelled as an unspecified subspecies. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An upright mustard with lance-shaped basal leaves, non-clasping upper leaves, yellow four-petaled flowers and slender seedpods. [CO-elongated-mustard](https://fremontcountyco.gov/sites/default/files/weed-control/weed-files/elongated-mustard-fact-sheet.pdf)
## Plants & habitat
Spreads by seed along disturbed, rocky and semi-arid ground. Prompt reporting helps prevent establishment. [CO-elongated-mustard](https://fremontcountyco.gov/sites/default/files/weed-control/weed-files/elongated-mustard-fact-sheet.pdf)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **CO-elongated-mustard** — [Elongated mustard identification and management](https://fremontcountyco.gov/sites/default/files/weed-control/weed-files/elongated-mustard-fact-sheet.pdf), Colorado Department of Agriculture, hosted by Fremont County. Accessed 2026-09-07T01:14:00+00:00. Locator: Identification and impacts; updated July 2015.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=elongated-mustard) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Reference photographs identify B. elongata subsp. integrifolia. Colorado lists B. elongata broadly. The fact sheet’s inconsistent sepal-count caption is not adopted.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| elongated-mustard-1 | Recognize | Species-specific | CO-elongated-mustard | No quantitative safe exposure established here. |
| elongated-mustard-2 | Plants & habitat | Species-specific | CO-elongated-mustard | No quantitative safe exposure established here. |
| elongated-mustard-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| elongated-mustard-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| elongated-mustard-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md
---
{
"id": "eurasian-watermilfoil",
"name": "Eurasian watermilfoil",
"scientific": "Myriophyllum spicatum",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Fragments spread dense aquatic growth",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Native milfoils and hybrids can look similar. Confirm identification before management; a feathery leaf is not enough.",
"source_ids": [
"CO-rules-2025",
"N-myriophyllum-spicatum",
"S27",
"Fremont-list-definitions"
],
"description": "Eurasian watermilfoil: Fragments spread dense aquatic growth. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-myriophyllum-spicatum"
],
"scope": "Species-specific",
"note": "",
"id": "eurasian-watermilfoil-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-myriophyllum-spicatum"
],
"scope": "Species-specific",
"note": "",
"id": "eurasian-watermilfoil-2"
},
{
"label": "People",
"sources": [
"N-myriophyllum-spicatum"
],
"scope": "Species-specific",
"note": "",
"id": "eurasian-watermilfoil-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "eurasian-watermilfoil-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "eurasian-watermilfoil-5"
},
{
"id": "eurasian-watermilfoil-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"eurasian-watermilfoil-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"eurasian-watermilfoil-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/eurasian-watermilfoil.md"
}
---
# Eurasian watermilfoil
*Myriophyllum spicatum*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Fragments spread dense aquatic growth.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Native milfoils and hybrids can look similar. Confirm identification before management; a feathery leaf is not enough.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**emergent flowering shoot** — A watermilfoil shoot at the water surface with a small flower spike rising above the water.
Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org; [CC BY 3.0 us](https://creativecommons.org/licenses/by/3.0/us/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Myriophyllum_spicatum_5447200_(cropped).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1c/Myriophyllum_spicatum_5447200_%28cropped%29.jpg). Source-identified photograph with visual consistency check Eurasian water-milfoil - Myriophyllum spicatum L. - United States Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**submerged foliage** — Fine, whorled watermilfoil foliage forming submerged branching growth in shallow water.
Photo: Donald Hobern from Copenhagen, Denmark; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Myriophyllum_spicatum_(7914509568).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/71/Myriophyllum_spicatum_%287914509568%29.jpg). Source-identified photograph with visual consistency check Myriophyllum spicatum L., Spiked Water-milfoil, Øregaard Museum grounds, Hellerup, Denmark, 1 September 2012 Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**female flowers** — Macro view of small female flowers in a whorl around a watermilfoil stem, with a 2 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Myriophyllum_spicatum_sl3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a8/Myriophyllum_spicatum_sl3.jpg). Source-identified photograph with visual consistency check Female flowers Taxonym: Myriophyllum spicatum ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Alte Donau, Vienna-Floridsdorf - ca. 160 m a.s.l. Habitat: oxbow lake Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Submerged, feather-like leaves occur in whorls; small flowering spikes emerge above the water. [N-myriophyllum-spicatum](https://plants.ces.ncsu.edu/plants/myriophyllum-spicatum/)
## Plants & habitat
Stem fragments spread readily. Dense growth crowds native plants and obstructs recreation and water infrastructure. [N-myriophyllum-spicatum](https://plants.ces.ncsu.edu/plants/myriophyllum-spicatum/)
## People
Dense growth interferes with swimming and boating; avoid entering heavily vegetated water. [N-myriophyllum-spicatum](https://plants.ces.ncsu.edu/plants/myriophyllum-spicatum/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-myriophyllum-spicatum** — [myriophyllum spicatum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/myriophyllum-spicatum/), NC State Extension. Accessed 2026-09-07T01:04:54+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=eurasian-watermilfoil) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Native milfoils and hybrids can look similar. Confirm identification before management; a feathery leaf is not enough.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| eurasian-watermilfoil-1 | Recognize | Species-specific | N-myriophyllum-spicatum | No quantitative safe exposure established here. |
| eurasian-watermilfoil-2 | Plants & habitat | Species-specific | N-myriophyllum-spicatum | No quantitative safe exposure established here. |
| eurasian-watermilfoil-3 | People | Species-specific | N-myriophyllum-spicatum | No quantitative safe exposure established here. |
| eurasian-watermilfoil-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| eurasian-watermilfoil-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/index.md
---
{
"id": "fernleaf-yarrow",
"name": "Fernleaf yarrow",
"scientific": "Achillea filipendulina",
"category": "xeriscape",
"status": "Introduced drought-tolerant perennial",
"status_sources": [
"N-achillea-filipendulina"
],
"warning": "Spreads; pet toxicity unresolved",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Do not merge this taxon with Achillea millefolium solely because both are called yarrow.",
"source_ids": [
"N-achillea-filipendulina",
"S08"
],
"description": "Fernleaf yarrow: Spreads; pet toxicity unresolved. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-achillea-filipendulina"
],
"scope": "Species-specific",
"note": "",
"id": "fernleaf-yarrow-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-achillea-filipendulina"
],
"scope": "Species-specific",
"note": "",
"id": "fernleaf-yarrow-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "This species-specific horticultural source does not establish human ingestion safety.",
"id": "fernleaf-yarrow-3"
},
{
"label": "Dogs & cats",
"sources": [
"S08"
],
"scope": "Different-species source; unresolved transfer",
"note": "",
"id": "fernleaf-yarrow-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "fernleaf-yarrow-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"fernleaf-yarrow-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"fernleaf-yarrow-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"fernleaf-yarrow-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/fernleaf-yarrow.md"
}
---
# Fernleaf yarrow
*Achillea filipendulina*
**Introduced drought-tolerant perennial.** [N-achillea-filipendulina](https://plants.ces.ncsu.edu/plants/achillea-filipendulina/)
> **Spreads; pet toxicity unresolved.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Do not merge this taxon with Achillea millefolium solely because both are called yarrow.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Macro view of a domed-to-flat cluster of small golden-yellow flower heads.
Photo: Yerpo; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Achillea_filipendulina_flowers.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3b/Achillea_filipendulina_flowers.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and leaf** — Upright yellow-flowering yarrow in bare stony soil, with fernlike divided leaves visible down the stems.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Achillea_filipendulina_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d4/Achillea_filipendulina_sl1.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**garden habit** — Tall garden clump with many flat golden-yellow flower clusters above fernlike green foliage.
Photo: Andrea Moro; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Achillea_filipendulina_plant_(01).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fa/Achillea_filipendulina_plant_%2801%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Tall stems hold flat yellow flower clusters above fern-like green leaves. [N-achillea-filipendulina](https://plants.ces.ncsu.edu/plants/achillea-filipendulina/)
## Plants & habitat
Tolerates dry sites and can crowd its space; divide as needed and avoid overwatering. Cultivars differ in seed production. [N-achillea-filipendulina](https://plants.ces.ncsu.edu/plants/achillea-filipendulina/)
## People
This species-specific horticultural source does not establish human ingestion safety. This is an evidence gap, not proof of safety.
## Dogs & cats
The ASPCA yarrow entry names Achillea millefolium. It does not resolve toxicity for A. filipendulina; prevent chewing while this gap remains. [S08](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow)
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-achillea-filipendulina** — [Achillea filipendulina — Plant Toolbox](https://plants.ces.ncsu.edu/plants/achillea-filipendulina/), NC State Extension. Accessed 2026-09-07T00:23:59+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
- **S08** — [Yarrow](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow), ASPCA Poison Control. Accessed 2026-09-07T00:23:53+00:00. Locator: Scientific Name; Toxicity; Clinical Signs.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=fernleaf-yarrow) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Do not merge this taxon with Achillea millefolium solely because both are called yarrow.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| fernleaf-yarrow-1 | Recognize | Species-specific | N-achillea-filipendulina | No quantitative exposure threshold established here. |
| fernleaf-yarrow-2 | Plants & habitat | Species-specific | N-achillea-filipendulina | No quantitative exposure threshold established here. |
| fernleaf-yarrow-3 | People | Review limitation | Review limitation | This species-specific horticultural source does not establish human ingestion safety. |
| fernleaf-yarrow-4 | Dogs & cats | Different-species source; unresolved transfer | S08 | No quantitative exposure threshold established here. |
| fernleaf-yarrow-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md
---
{
"id": "field-bindweed",
"name": "Field bindweed",
"scientific": "Convolvulus arvensis",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"C-descriptions"
],
"warning": "Smothers plants; livestock concern",
"warning_tone": "caution",
"aliases": [
"field morning-glory"
],
"taxonomy_note": "Morning glory is an ambiguous common name. Ipomoea poison listings do not automatically apply to Convolvulus arvensis.",
"source_ids": [
"C-descriptions",
"N-convolvulus-arvensis",
"K-bindweed",
"Fremont-list-definitions"
],
"description": "Field bindweed: Smothers plants; livestock concern. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "field-bindweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-convolvulus-arvensis",
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "field-bindweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "This review did not establish human ingestion effects.",
"id": "field-bindweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "field-bindweed-4"
},
{
"label": "Other animals",
"sources": [
"K-bindweed"
],
"scope": "Species-specific",
"note": "",
"id": "field-bindweed-5"
},
{
"id": "field-bindweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"field-bindweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"field-bindweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"field-bindweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/field-bindweed.md"
}
---
# Field bindweed
*Convolvulus arvensis*
**Colorado noxious weed · List C — Manage widespread weeds.** [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Smothers plants; livestock concern.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Morning glory is an ambiguous common name. Ipomoea poison listings do not automatically apply to Convolvulus arvensis.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Pale pink funnel-shaped flowers with darker pink bands and nearby arrow-shaped leaves.
Photo: Svklimkin; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Convolvulus_arvensis_11.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e8/Convolvulus_arvensis_11.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Trailing vine along a path edge with several funnel-shaped white flowers and arrow-shaped leaves.
Photo: Anna.Massini; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Gruppo_di_campanelle_di_prato_detto_anche_imbutino_-_group_of_Field_Bindweed_-_Convolvulus_arvensis.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/98/Gruppo_di_campanelle_di_prato_detto_anche_imbutino_-_group_of_Field_Bindweed_-_Convolvulus_arvensis.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-flower** — Arrow-shaped leaves on a slender climbing stem beside a white funnel-shaped flower.
Photo: Frank Vincentz; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Convolvulus_arvensis6_ies.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f9/Convolvulus_arvensis6_ies.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Twining or trailing vines with arrowhead leaves and white to pink funnel-shaped flowers. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Plants & habitat
Deep roots and persistent seed make control difficult. Vines overgrow neighboring plants; repeated shoot removal and a site-specific plan are usually needed. [N-convolvulus-arvensis](https://plants.ces.ncsu.edu/plants/convolvulus-arvensis/) [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## People
This review did not establish human ingestion effects. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Cornell reports alkaloids that can cause digestive problems in some livestock. Pet effects and a safe feeding threshold are not established here. [K-bindweed](https://blogs.cornell.edu/weedid/859-2/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **N-convolvulus-arvensis** — [Convolvulus arvensis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/convolvulus-arvensis/), NC State Extension. Accessed 2026-09-07T00:24:00+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
- **K-bindweed** — [Bindweeds: field and hedge bindweed](https://blogs.cornell.edu/weedid/859-2/), Cornell University. Accessed 2026-09-07T00:31:29+00:00. Locator: Field bindweed description, alkaloids and livestock, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=field-bindweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Morning glory is an ambiguous common name. Ipomoea poison listings do not automatically apply to Convolvulus arvensis.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| field-bindweed-1 | Recognize | Species-specific | C-descriptions | No quantitative exposure threshold established here. |
| field-bindweed-2 | Plants & habitat | Species-specific | N-convolvulus-arvensis, C-descriptions | No quantitative exposure threshold established here. |
| field-bindweed-3 | People | Review limitation | Review limitation | This review did not establish human ingestion effects. |
| field-bindweed-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| field-bindweed-5 | Other animals | Species-specific | K-bindweed | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md
---
{
"id": "flowering-rush",
"name": "Flowering rush",
"scientific": "Butomus umbellatus",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Small fragments spread aquatic colonies",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Grass-like aquatic plants may not be flowering when found. Leaf bases and submerged structures matter for identification.",
"source_ids": [
"CO-rules-2025",
"WA-flowering-rush",
"S27",
"Fremont-list-definitions"
],
"description": "Flowering rush: Small fragments spread aquatic colonies. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-flowering-rush"
],
"scope": "Species-specific",
"note": "",
"id": "flowering-rush-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-flowering-rush"
],
"scope": "Species-specific",
"note": "",
"id": "flowering-rush-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "flowering-rush-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "flowering-rush-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "flowering-rush-5"
},
{
"id": "flowering-rush-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"flowering-rush-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"flowering-rush-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"flowering-rush-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/flowering-rush.md"
}
---
# Flowering rush
*Butomus umbellatus*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Small fragments spread aquatic colonies.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Grass-like aquatic plants may not be flowering when found. Leaf bases and submerged structures matter for identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering umbel** — A cluster of pale pink flowers and buds held on radiating stalks beside open water.
Photo: Jacek Pietruszewski; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/29862742); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/46629677/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Open pale pink flowers showing six floral segments and red-tipped reproductive structures.
Photo: Jacek Pietruszewski; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/29862742); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/46629761/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Flowering stems rising above narrow shoreline leaves beside a waterbody.
Photo: Jacek Pietruszewski; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/29862742); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/46629836/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An aquatic perennial with slender leaves, triangular leaf bases and clusters of pale pink flowers on tall stalks. [WA-flowering-rush](https://www.nwcb.wa.gov/weeds/flowering-rush)
## Plants & habitat
Rhizome fragments and small vegetative bulbils enable spread. Casual digging can release propagules into the water; obtain a site-specific management plan. [WA-flowering-rush](https://www.nwcb.wa.gov/weeds/flowering-rush)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-flowering-rush** — [Flowering Rush](https://www.nwcb.wa.gov/weeds/flowering-rush), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:08:59+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=flowering-rush) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Grass-like aquatic plants may not be flowering when found. Leaf bases and submerged structures matter for identification.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| flowering-rush-1 | Recognize | Species-specific | WA-flowering-rush | No quantitative safe exposure established here. |
| flowering-rush-2 | Plants & habitat | Species-specific | WA-flowering-rush | No quantitative safe exposure established here. |
| flowering-rush-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| flowering-rush-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| flowering-rush-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md
---
{
"id": "foxtail-barley",
"name": "Foxtail barley",
"scientific": "Hordeum jubatum",
"category": "native",
"status": "Colorado native",
"status_sources": [
"C-foxtail"
],
"warning": "Barbed seed awns injure animals",
"warning_tone": "caution",
"aliases": [
"squirreltail barley"
],
"taxonomy_note": "",
"source_ids": [
"C-foxtail",
"S22"
],
"description": "Foxtail barley: Barbed seed awns injure animals. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-foxtail"
],
"scope": "Species-specific",
"note": "",
"id": "foxtail-barley-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-foxtail"
],
"scope": "Species-specific",
"note": "",
"id": "foxtail-barley-2"
},
{
"label": "People",
"sources": [
"C-foxtail"
],
"scope": "Editorial physical-risk inference",
"note": "",
"id": "foxtail-barley-3"
},
{
"label": "Dogs & cats",
"sources": [
"S22"
],
"scope": "Grass-awn group; not a species-specific pet case series",
"note": "",
"id": "foxtail-barley-4"
},
{
"label": "Other animals",
"sources": [
"C-foxtail"
],
"scope": "Species-specific",
"note": "",
"id": "foxtail-barley-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/foxtail-barley.md"
}
---
# Foxtail barley
*Hordeum jubatum*
**Colorado native.** [C-foxtail](https://extension.colostate.edu/resource/foxtail-barley/)
> **Barbed seed awns injure animals.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**whole plant** — A tuft of foxtail barley with slender leaves and pale pink, long-awned heads.
Photo: Diego Delso; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Hordeum_jubatum,_Refugio_Nacional_de_Vida_Silvestre_Tetlin,_Alaska,_Estados_Unidos,_2017-08-24,_DD_33.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a2/Hordeum_jubatum%2C_Refugio_Nacional_de_Vida_Silvestre_Tetlin%2C_Alaska%2C_Estados_Unidos%2C_2017-08-24%2C_DD_33.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf junction detail** — Close view of the leaf sheath and blade junction, including the membranous ligule.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Hordeum_jubatum_15-p.bot-horde.jubatu-04.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4e/Hordeum_jubatum_15-p.bot-horde.jubatu-04.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seed structure** — A detached awned spikelet photographed against a millimetre ruler.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Hordeum_jubatum_15-p.bot-horde.jubatu-17.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/91/Hordeum_jubatum_15-p.bot-horde.jubatu-17.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A short-lived perennial bunchgrass with silky, often pink-tinged seedheads. It commonly occupies moist, disturbed or saline sites. [C-foxtail](https://extension.colostate.edu/resource/foxtail-barley/)
## Plants & habitat
Can increase under heavy grazing as livestock avoid mature seedheads. Management should reduce seed production and support desirable grasses. [C-foxtail](https://extension.colostate.edu/resource/foxtail-barley/)
## People
Sharp seed awns can catch on clothing; avoiding direct contact is a physical-risk precaution. This is not a chemical-poison diagnosis. [C-foxtail](https://extension.colostate.edu/resource/foxtail-barley/)
*Evidence scope: Editorial physical-risk inference.*
## Dogs & cats
Grass awns can lodge in tissue and migrate, causing serious injury. Avoid mature seedheads and seek veterinary assessment for suspected embedded awns. The pet source discusses foxtails broadly. [S22](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails)
*Evidence scope: Grass-awn group; not a species-specific pet case series.*
## Other animals
Mature awns injure livestock mouths, noses and eyes. Contaminated hay is unsafe and should not be fed or sold. [C-foxtail](https://extension.colostate.edu/resource/foxtail-barley/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-foxtail** — [Foxtail barley](https://extension.colostate.edu/resource/foxtail-barley/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S22** — [Foxtails and Dogs](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails), UC Davis · School of Veterinary Medicine. Accessed 2026-09-06. Locator: Takeaways; signs; prevention.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=foxtail-barley) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| foxtail-barley-1 | Recognize | Species-specific | C-foxtail | No quantitative exposure threshold established here. |
| foxtail-barley-2 | Plants & habitat | Species-specific | C-foxtail | No quantitative exposure threshold established here. |
| foxtail-barley-3 | People | Editorial physical-risk inference | C-foxtail | No quantitative exposure threshold established here. |
| foxtail-barley-4 | Dogs & cats | Grass-awn group; not a species-specific pet case series | S22 | No quantitative exposure threshold established here. |
| foxtail-barley-5 | Other animals | Species-specific | C-foxtail | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/index.md
---
{
"id": "fringed-sage",
"name": "Fringed sage",
"scientific": "Artemisia frigida",
"category": "xeriscape",
"status": "Colorado native; low-water garden plant",
"status_sources": [
"S03"
],
"warning": "Spreading growth; pet evidence gap",
"warning_tone": "caution",
"aliases": [
"fringed sagebrush"
],
"taxonomy_note": "Artemisia species differ chemically. Do not infer toxicity or medicinal uses from a different sage or sagebrush.",
"source_ids": [
"S03",
"F-fringed"
],
"description": "Fringed sage: Spreading growth; pet evidence gap. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-fringed"
],
"scope": "Species-specific",
"note": "",
"id": "fringed-sage-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-fringed"
],
"scope": "Species-specific habit; garden judgment",
"note": "",
"id": "fringed-sage-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human ingestion safety was not established in the reviewed gardening and ecological sources.",
"id": "fringed-sage-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "fringed-sage-4"
},
{
"label": "Other animals",
"sources": [
"S03"
],
"scope": "Species-specific",
"note": "",
"id": "fringed-sage-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"fringed-sage-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"fringed-sage-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"fringed-sage-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/fringed-sage.md"
}
---
# Fringed sage
*Artemisia frigida*
**Colorado native; low-water garden plant.** [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf)
> **Spreading growth; pet evidence gap.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Artemisia species differ chemically. Do not infer toxicity or medicinal uses from a different sage or sagebrush.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**basal foliage** — Low basal shoots with compact clusters of finely divided silvery-green leaves among dry vegetation.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_frigida_(3299645583).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/58/Artemisia_frigida_%283299645583%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering habit** — Rounded silvery plant with finely divided foliage and many small yellow flower heads on upright branches.
Photo: Jim Pisarowicz; [Public domain](https://commons.wikimedia.org/wiki/File:Artemisia_frigida_NPS-1.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_frigida_NPS-1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/62/Artemisia_frigida_NPS-1.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature habit** — Low mound of silvery basal leaves beneath tall, slender pale reproductive stems on a grassy slope.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_frigida_(5034482272).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1b/Artemisia_frigida_%285034482272%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A low, aromatic, silvery native with finely divided foliage and a woody base. [F-fringed](https://research.fs.usda.gov/feis/species-reviews/artfri)
## Plants & habitat
Forms spreading mats and produces seed. Garden judgment: use where low spreading growth fits, then manage volunteers. [F-fringed](https://research.fs.usda.gov/feis/species-reviews/artfri)
## People
Human ingestion safety was not established in the reviewed gardening and ecological sources. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
The Front Range guide records pollen and seed value. Wildlife use does not establish pet or livestock feeding safety. [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S03** — [Low-Water Native Plants for Colorado Gardens: Front Range & Foothills](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf), Colorado Native Plant Society / CSU Extension. Accessed 2026-09-07T00:23:53+00:00. Locator: Plant table: Asclepias speciosa and Achillea millefolium.
- **F-fringed** — [Artemisia frigida species review](https://research.fs.usda.gov/feis/species-reviews/artfri), US Forest Service. Accessed 2026-09-07T00:27:21+00:00. Locator: Description, distribution, hazards, management; see claim locator.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=fringed-sage) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Artemisia species differ chemically. Do not infer toxicity or medicinal uses from a different sage or sagebrush.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| fringed-sage-1 | Recognize | Species-specific | F-fringed | No quantitative exposure threshold established here. |
| fringed-sage-2 | Plants & habitat | Species-specific habit; garden judgment | F-fringed | No quantitative exposure threshold established here. |
| fringed-sage-3 | People | Review limitation | Review limitation | Human ingestion safety was not established in the reviewed gardening and ecological sources. |
| fringed-sage-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| fringed-sage-5 | Other animals | Species-specific | S03 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/index.md
---
{
"id": "giant-knotweed",
"name": "Giant knotweed",
"scientific": "Reynoutria sachalinensis",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Very persistent riparian colonies",
"warning_tone": "caution",
"aliases": [
"Fallopia sachalinense",
"Fallopia sachalinensis",
"Polygonum sachalinense"
],
"taxonomy_note": "The state rule uses Fallopia sachalinense. Giant, Japanese and Bohemian knotweeds overlap in appearance; confirm identity beyond plant height.",
"source_ids": [
"CO-rules-2025",
"WA-giant-knotweed",
"S27",
"Fremont-list-definitions"
],
"description": "Giant knotweed: Very persistent riparian colonies. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-giant-knotweed"
],
"scope": "Species-specific",
"note": "",
"id": "giant-knotweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-giant-knotweed"
],
"scope": "Species-specific",
"note": "",
"id": "giant-knotweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-knotweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-knotweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-knotweed-5"
},
{
"id": "giant-knotweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"giant-knotweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"giant-knotweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"giant-knotweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/giant-knotweed.md"
}
---
# Giant knotweed
*Reynoutria sachalinensis*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Very persistent riparian colonies.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The state rule uses Fallopia sachalinense. Giant, Japanese and Bohemian knotweeds overlap in appearance; confirm identity beyond plant height.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leafy shoots** — Upright shoots with broad, heart-based leaves among mixed ground vegetation.
Photo: Oleksandr Shynder; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/101817066); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/170078727/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Giant knotweed can be confused with Bohemian knotweed. Identification follows the research-grade source; leaf-base and magnified hair views are included, but photos alone do not establish hybrid ancestry. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf shape** — Broad leaves with visibly heart-shaped bases and prominent veins.
Photo: Oleksandr Shynder; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/101817066); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/170078917/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Giant knotweed can be confused with Bohemian knotweed. Identification follows the research-grade source; leaf-base and magnified hair views are included, but photos alone do not establish hybrid ancestry. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf hairs** — Magnified leaf surface showing long, slender hairs near veins; the circular viewing field is part of the source photo.
Photo: Oleksandr Shynder; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/101817066); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/170079644/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Giant knotweed can be confused with Bohemian knotweed. Identification follows the research-grade source; leaf-base and magnified hair views are included, but photos alone do not establish hybrid ancestry. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Very large, heart-based leaves on hollow, jointed stems; small greenish-white flower clusters arise near upper leaves. [WA-giant-knotweed](https://www.nwcb.wa.gov/weeds/giant-knotweed)
## Plants & habitat
Rhizomes form dense colonies and even small fragments can regenerate. Keep cut material and contaminated soil from spreading. [WA-giant-knotweed](https://www.nwcb.wa.gov/weeds/giant-knotweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-giant-knotweed** — [Giant Knotweed](https://www.nwcb.wa.gov/weeds/giant-knotweed), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:00+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=giant-knotweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The state rule uses Fallopia sachalinense. Giant, Japanese and Bohemian knotweeds overlap in appearance; confirm identity beyond plant height.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| giant-knotweed-1 | Recognize | Species-specific | WA-giant-knotweed | No quantitative safe exposure established here. |
| giant-knotweed-2 | Plants & habitat | Species-specific | WA-giant-knotweed | No quantitative safe exposure established here. |
| giant-knotweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-knotweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-knotweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md
---
{
"id": "giant-ragweed",
"name": "Giant ragweed",
"scientific": "Ambrosia trifida",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Allergenic pollen and strong competition in disturbed ground",
"warning_tone": "caution",
"aliases": [
"great ragweed"
],
"taxonomy_note": "Giant ragweed is Ambrosia trifida. A mismatched Latin name in the compared manufacturer guide is not adopted. Common ragweed and western ragweed have their own profiles.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"I-giant-ragweed",
"C-ragweed-native",
"S27"
],
"description": "Giant ragweed: Allergenic pollen and strong competition in disturbed ground. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"I-giant-ragweed"
],
"scope": "Species-specific",
"note": "",
"id": "giant-ragweed-1"
},
{
"label": "People",
"sources": [
"I-giant-ragweed",
"C-ragweed-native"
],
"scope": "Species-specific",
"note": "",
"id": "giant-ragweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-ragweed-3"
},
{
"label": "Other animals",
"sources": [
"I-giant-ragweed"
],
"scope": "Forage observation; safety limitation",
"note": "",
"id": "giant-ragweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"I-giant-ragweed"
],
"scope": "Species-specific",
"note": "",
"id": "giant-ragweed-5"
},
{
"label": "Management & timing",
"sources": [
"C-ragweed-native"
],
"scope": "Species-specific",
"note": "",
"id": "giant-ragweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"giant-ragweed-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"giant-ragweed-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 32; Ambrosia trifida",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Ambrosia trifida"
},
"source": "content/plants/giant-ragweed.md"
}
---
# Giant ragweed
*Ambrosia trifida*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Allergenic pollen and strong competition in disturbed ground.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Giant ragweed is Ambrosia trifida. A mismatched Latin name in the compared manufacturer guide is not adopted. Common ragweed and western ragweed have their own profiles.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — An upright giant ragweed plant beside a fence, with large three- to five-lobed leaves.
Photo: GTBacchus; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_trifida_full_shot.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/97/Ambrosia_trifida_full_shot.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Giant ragweed leaves may be simple, three-lobed or five-lobed. The photographs retain the exact source species identification. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves and stem** — Large lobed, toothed leaves arranged along a sturdy green stem.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_trifida_15-p.bot-ambro.trifi-08.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e4/Ambrosia_trifida_15-p.bot-ambro.trifi-08.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Giant ragweed leaves may be simple, three-lobed or five-lobed. The photographs retain the exact source species identification. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowering habit** — Several tall leafy shoots carrying slender terminal spikes of green flower heads.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Ambrosia_trifida_15-p.bot-ambro.trifi-06.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/59/Ambrosia_trifida_15-p.bot-ambro.trifi-06.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Giant ragweed leaves may be simple, three-lobed or five-lobed. The photographs retain the exact source species identification. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An annual with rough stems and opposite leaves, usually with three to five deep lobes. Early leaves may be unlobed. Male flower clusters stand at the stem tips. [I-giant-ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed)
## People
Windborne pollen is a significant hay-fever trigger for susceptible people. Colorado extension describes late-season ragweed exposure; local timing varies with weather. [I-giant-ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed) [C-ragweed-native](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Some animals browse the foliage; that does not establish a safe feed amount or a pet-safety rating. [I-giant-ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed)
*Evidence scope: Forage observation; safety limitation.*
## Plants & habitat
Early emergence and tall growth can help it dominate disturbed sites. Resistance to some herbicide groups is documented in particular populations. [I-giant-ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed)
## Management & timing
Remove young plants before flowering and seed formation. For a large or persistent infestation, consult a local weed specialist about identification and resistance. [C-ragweed-native](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **I-giant-ragweed** — [Giant ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed), Iowa State University Extension. Accessed 2026-09-07T02:26:09+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **C-ragweed-native** — [Ragweed](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf), Colorado State University Extension. Accessed 2026-09-07T02:26:09+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=giant-ragweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 32; Ambrosia trifida. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Giant ragweed is Ambrosia trifida. A mismatched Latin name in the compared manufacturer guide is not adopted. Common ragweed and western ragweed have their own profiles.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| giant-ragweed-1 | Identification | Species-specific | I-giant-ragweed | No quantitative safe exposure established here. |
| giant-ragweed-2 | People | Species-specific | I-giant-ragweed, C-ragweed-native | No quantitative safe exposure established here. |
| giant-ragweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-ragweed-4 | Other animals | Forage observation; safety limitation | I-giant-ragweed | No quantitative safe exposure established here. |
| giant-ragweed-5 | Plants & habitat | Species-specific | I-giant-ragweed | No quantitative safe exposure established here. |
| giant-ragweed-6 | Management & timing | Species-specific | C-ragweed-native | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md
---
{
"id": "giant-reed",
"name": "Giant reed",
"scientific": "Arundo donax",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Dense stands displace riparian plants",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "This is a grass, not a true bamboo. Variegated garden cultivars are not evidence of an exemption from the listed species.",
"source_ids": [
"CO-rules-2025",
"N-arundo-donax",
"S27",
"Fremont-list-definitions"
],
"description": "Giant reed: Dense stands displace riparian plants. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-arundo-donax"
],
"scope": "Species-specific",
"note": "",
"id": "giant-reed-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-arundo-donax"
],
"scope": "Species-specific",
"note": "",
"id": "giant-reed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-reed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-reed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-reed-5"
},
{
"id": "giant-reed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"giant-reed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"giant-reed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"giant-reed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/giant-reed.md"
}
---
# Giant reed
*Arundo donax*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Dense stands displace riparian plants.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is a grass, not a true bamboo. Variegated garden cultivars are not evidence of an exemption from the listed species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**stand** — A dense stand of tall, jointed canes and long leaves near water.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/332542446); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/603525902/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stems** — Lower and middle portions of a dense cane stand, with visible upright stems and leaf sheaths.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/332542446); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/603526724/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage and nodes** — A leafy cane showing broad, arching blades attached at successive nodes.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/332542446); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/603526777/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A very tall, bamboo-like grass with broad clasping leaves and large, feathery flower plumes. [N-arundo-donax](https://plants.ces.ncsu.edu/plants/arundo-donax/)
## Plants & habitat
Rapid rhizome growth crowds out other plants. Stem nodes can root; moving cut material can spread an infestation. [N-arundo-donax](https://plants.ces.ncsu.edu/plants/arundo-donax/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-arundo-donax** — [arundo donax — Plant Toolbox](https://plants.ces.ncsu.edu/plants/arundo-donax/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=giant-reed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is a grass, not a true bamboo. Variegated garden cultivars are not evidence of an exemption from the listed species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| giant-reed-1 | Recognize | Species-specific | N-arundo-donax | No quantitative safe exposure established here. |
| giant-reed-2 | Plants & habitat | Species-specific | N-arundo-donax | No quantitative safe exposure established here. |
| giant-reed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-reed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-reed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md
---
{
"id": "giant-salvinia",
"name": "Giant salvinia",
"scientific": "Salvinia molesta",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Floating mats harm aquatic habitat",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.",
"source_ids": [
"CO-rules-2025",
"N-salvinia-molesta",
"S27",
"Fremont-list-definitions"
],
"description": "Giant salvinia: Floating mats harm aquatic habitat. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-salvinia-molesta"
],
"scope": "Species-specific",
"note": "",
"id": "giant-salvinia-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-salvinia-molesta"
],
"scope": "Species-specific",
"note": "",
"id": "giant-salvinia-2"
},
{
"label": "People",
"sources": [
"N-salvinia-molesta"
],
"scope": "Species-specific",
"note": "",
"id": "giant-salvinia-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "giant-salvinia-4"
},
{
"label": "Other animals",
"sources": [
"N-salvinia-molesta"
],
"scope": "Species-specific",
"note": "",
"id": "giant-salvinia-5"
},
{
"id": "giant-salvinia-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"giant-salvinia-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"giant-salvinia-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/giant-salvinia.md"
}
---
# Giant salvinia
*Salvinia molesta*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Floating mats harm aquatic habitat.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**floating foliage** — Close view of floating, folded green leaves with textured upper surfaces.
Photo: Ixitixel; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_(Habitus)_3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/98/Salvinia_molesta_%28Habitus%29_3.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf surface** — Floating folded leaves with water droplets; the source describes this as a photograph focus-stacked from 20 exposures.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_kz16.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/21/Salvinia_molesta_kz16.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Source photographer describes the original as focus-stacked from 20 exposures. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**infestation** — Lake Wilson in Hawaii covered by a dense salvinia mat, with a vehicle and boat on the near shore.
Photo: Nani Shimakuku, U.S. Army Corps of Engineers; [Public domain](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_covering_lake.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Salvinia_molesta_covering_lake.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3d/Salvinia_molesta_covering_lake.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Salvinia species can be similar. The selected images follow source identifications; the diagnostic joined hair tips are not resolved clearly in every view. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A floating fern with paired surface fronds and submerged, root-like fronds. Magnification reveals characteristic joined, eggbeater-shaped hairs. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)
## Plants & habitat
Thick mats restrict light and oxygen, clog water intakes and obstruct recreation. Do not introduce it into ponds or discard aquarium material outdoors. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)
## People
Dense surface mats obstruct boating and swimming; this is a water-access hazard rather than a demonstrated ingestion syndrome. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Habitat effects include reduced oxygen and harm to fish and aquatic plants. Direct livestock toxicity is not established here. [N-salvinia-molesta](https://plants.ces.ncsu.edu/plants/salvinia-molesta/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-salvinia-molesta** — [salvinia molesta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/salvinia-molesta/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=giant-salvinia) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Several floating ferns look similar. Close inspection of leaf hairs is needed; no photo alone establishes identification.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| giant-salvinia-1 | Recognize | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-2 | Plants & habitat | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-3 | People | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
| giant-salvinia-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| giant-salvinia-5 | Other animals | Species-specific | N-salvinia-molesta | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/index.md
---
{
"id": "golden-banner",
"name": "Golden banner",
"scientific": "Thermopsis divaricarpa",
"category": "native",
"status": "Colorado native",
"status_sources": [
"C-perennials"
],
"warning": "May poison livestock",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Do not silently substitute Thermopsis montana or T. lupinoides studies for T. divaricarpa.",
"source_ids": [
"C-perennials",
"C-banner"
],
"description": "Golden banner: May poison livestock. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-perennials"
],
"scope": "Species-specific",
"note": "",
"id": "golden-banner-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-perennials"
],
"scope": "Reported spread; garden judgment",
"note": "",
"id": "golden-banner-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "This review has no species-specific human exposure assessment.",
"id": "golden-banner-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "golden-banner-4"
},
{
"label": "Other animals",
"sources": [
"C-banner"
],
"scope": "Species-specific",
"note": "",
"id": "golden-banner-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"golden-banner-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"golden-banner-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/golden-banner.md"
}
---
# Golden banner
*Thermopsis divaricarpa*
**Colorado native.** [C-perennials](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/)
> **May poison livestock.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Do not silently substitute Thermopsis montana or T. lupinoides studies for T. divaricarpa.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**buds and leaves** — An upright shoot with yellow flower buds and emerging flowers above leafy nodes and broad stipules.
Photo: Laura J. Costello; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/20172084); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/31122443/original.jpg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering stem** — An upright raceme of open yellow pea-shaped flowers above trifoliate foliage.
Photo: Shalana Gray; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/113455763); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/191679085/original.jpg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**pods and leaves** — Dark, slender spreading pods on a branched stalk above green trifoliate leaves.
Photo: Curtis Drake; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/235648749); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/419116154/original.jpeg). The photo belongs to an iNaturalist research-grade observation identified as the named taxon; source taxon, quality grade, and identifications are retained. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Upright spikes of yellow, pea-like flowers on a native perennial. [C-perennials](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/)
## Plants & habitat
Spreads vigorously by rhizomes. Give it room in a garden; its ability to crowd smaller neighbors is a garden-management concern. [C-perennials](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/)
## People
This review has no species-specific human exposure assessment. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
CSU Extension’s Boulder County livestock guide lists this exact species among native plants that may be poisonous to livestock. No safe dose or safe growth stage is established here. [C-banner](https://boulder.extension.colostate.edu/wp-content/uploads/sites/7/2021/03/BoCo-Rural-Living-Guide-Agriculture-Livestock-Rev-1.pdf)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-perennials** — [Native Herbaceous Perennials for Colorado Landscapes](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/), Colorado State University Extension. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
- **C-banner** — [Rural Living Guide: Agriculture and Livestock](https://boulder.extension.colostate.edu/wp-content/uploads/sites/7/2021/03/BoCo-Rural-Living-Guide-Agriculture-Livestock-Rev-1.pdf), CSU Extension, Boulder County. Accessed 2026-09-07T00:31:28+00:00. Locator: Other Common Plants that may be Poisonous to Livestock: Golden Banner (Thermopsis divaricarpa).
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=golden-banner) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Do not silently substitute Thermopsis montana or T. lupinoides studies for T. divaricarpa.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| golden-banner-1 | Recognize | Species-specific | C-perennials | No quantitative exposure threshold established here. |
| golden-banner-2 | Plants & habitat | Reported spread; garden judgment | C-perennials | No quantitative exposure threshold established here. |
| golden-banner-3 | People | Review limitation | Review limitation | This review has no species-specific human exposure assessment. |
| golden-banner-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| golden-banner-5 | Other animals | Species-specific | C-banner | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/index.md
---
{
"id": "green-foxtail",
"name": "Green foxtail",
"scientific": "Setaria viridis",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Identify the grass behind the name “foxtail”",
"warning_tone": "caution",
"aliases": [
"green bristlegrass"
],
"taxonomy_note": "Setaria viridis is distinct from foxtail barley (Hordeum jubatum), giant foxtail (Setaria faberi) and yellow foxtail (Setaria pumila).",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-setaria-viridis",
"C-descriptions",
"S27"
],
"description": "Green foxtail: Identify the grass behind the name “foxtail”. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-setaria-viridis"
],
"scope": "Species-specific",
"note": "",
"id": "green-foxtail-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "green-foxtail-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-setaria-viridis"
],
"scope": "Review limitation",
"note": "",
"id": "green-foxtail-3"
},
{
"label": "Other animals",
"sources": [
"N-setaria-viridis"
],
"scope": "Species-specific",
"note": "",
"id": "green-foxtail-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-setaria-viridis"
],
"scope": "Species-specific",
"note": "",
"id": "green-foxtail-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "green-foxtail-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"green-foxtail-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"green-foxtail-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 79; Setaria viridis",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Setaria viridis"
},
"source": "content/plants/green-foxtail.md"
}
---
# Green foxtail
*Setaria viridis*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Identify the grass behind the name “foxtail”.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Setaria viridis is distinct from foxtail barley (Hordeum jubatum), giant foxtail (Setaria faberi) and yellow foxtail (Setaria pumila).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**inflorescence** — A curved green flower head is surrounded by many long fine bristles.
Photo: Petr Filippov; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Setaria_viridis.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2a/Setaria_viridis.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified S. viridis. Other foxtails resemble it; the collar, bristles and spikelet characters need examination on an unknown specimen. A gallery photograph labeled S. faberi was excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — Leafy green grass clumps with upright bristly flower heads at a path edge.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Groene_naaldaar_plant_(Setaria_viridis).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/38/Groene_naaldaar_plant_%28Setaria_viridis%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified S. viridis. Other foxtails resemble it; the collar, bristles and spikelet characters need examination on an unknown specimen. A gallery photograph labeled S. faberi was excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-collar** — Photographed grass leaf bases show the collar and ligule region against a wooden background.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Groene_naaldaar_ligula_(Setaria_viridis).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e3/Groene_naaldaar_ligula_%28Setaria_viridis%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified S. viridis. Other foxtails resemble it; the collar, bristles and spikelet characters need examination on an unknown specimen. A gallery photograph labeled S. faberi was excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A summer annual grass with narrow, bristly, cylindrical seedheads. Several bristles surround each small spikelet. It commonly grows in disturbed ground and lawns. [N-setaria-viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The botanical sources describe bristly seedheads but do not establish the injury rate or ingestion toxicity of this species in pets. Avoid applying foxtail barley or cheatgrass exposure findings to every grass called foxtail. [N-setaria-viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/)
## Other animals
Grazing animals and small mammals eat this grass, but that observation does not provide a safe feeding amount or prove that mature seedheads are harmless. [N-setaria-viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/)
## Plants & habitat
It produces abundant seed and can spread rapidly on disturbed sites. Dense established vegetation is less vulnerable than open, poor-quality ground. [N-setaria-viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/)
## Management & timing
Repair bare lawn patches and prevent seed production. A mowed plant may still form seedheads, so inspect close to the ground. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-setaria-viridis** — [Setaria viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=green-foxtail) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 79; Setaria viridis. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Setaria viridis is distinct from foxtail barley (Hordeum jubatum), giant foxtail (Setaria faberi) and yellow foxtail (Setaria pumila).
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| green-foxtail-1 | Identification | Species-specific | N-setaria-viridis | No quantitative safe exposure established here. |
| green-foxtail-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| green-foxtail-3 | Dogs & cats | Review limitation | N-setaria-viridis | No quantitative safe exposure established here. |
| green-foxtail-4 | Other animals | Species-specific | N-setaria-viridis | No quantitative safe exposure established here. |
| green-foxtail-5 | Plants & habitat | Species-specific | N-setaria-viridis | No quantitative safe exposure established here. |
| green-foxtail-6 | Management & timing | Species-specific | C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/index.md
---
{
"id": "hairy-willow-herb",
"name": "Hairy willow-herb",
"scientific": "Epilobium hirsutum",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Spreads through wetland vegetation",
"warning_tone": "caution",
"aliases": [
"hairy willowherb",
"great willowherb"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-epilobium-hirsutum",
"S27",
"Fremont-list-definitions"
],
"description": "Hairy willow-herb: Spreads through wetland vegetation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-epilobium-hirsutum"
],
"scope": "Species-specific",
"note": "",
"id": "hairy-willow-herb-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-epilobium-hirsutum"
],
"scope": "Species-specific",
"note": "",
"id": "hairy-willow-herb-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hairy-willow-herb-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hairy-willow-herb-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hairy-willow-herb-5"
},
{
"id": "hairy-willow-herb-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"hairy-willow-herb-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"hairy-willow-herb-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"hairy-willow-herb-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/hairy-willow-herb.md"
}
---
# Hairy willow-herb
*Epilobium hirsutum*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spreads through wetland vegetation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf and stem** — A serrated leaf and visibly hairy stem among surrounding vegetation.
Photo: Mathias keraudren; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Epilobium_hirsutum_04.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e9/Epilobium_hirsutum_04.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**young shoot** — A reddish young leafy shoot emerging from soil in spring.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Epilobium_hirsutum_2017-04-23_8522.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4a/Epilobium_hirsutum_2017-04-23_8522.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering shoot** — A leafy upright shoot with a pink flower and long buds beside water.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Epilobium_hirsutum_sl7.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c0/Epilobium_hirsutum_sl7.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Hairy stems and toothed leaves bear pink, four-petaled flowers with notched tips. Long capsules release hairy seeds. [N-epilobium-hirsutum](https://plants.ces.ncsu.edu/plants/epilobium-hirsutum/)
## Plants & habitat
Rhizomes and wind-carried seeds spread this wet-site plant. Inspect nursery stock and prevent seed dispersal. [N-epilobium-hirsutum](https://plants.ces.ncsu.edu/plants/epilobium-hirsutum/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-epilobium-hirsutum** — [epilobium hirsutum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/epilobium-hirsutum/), NC State Extension. Accessed 2026-09-07T01:04:51+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hairy-willow-herb) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hairy-willow-herb-1 | Recognize | Species-specific | N-epilobium-hirsutum | No quantitative safe exposure established here. |
| hairy-willow-herb-2 | Plants & habitat | Species-specific | N-epilobium-hirsutum | No quantitative safe exposure established here. |
| hairy-willow-herb-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hairy-willow-herb-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hairy-willow-herb-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md
---
{
"id": "halogeton",
"name": "Halogeton",
"scientific": "Halogeton glomeratus",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Severe oxalate poisoning in livestock",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"A-halogeton",
"S27",
"Fremont-list-definitions"
],
"description": "Halogeton: Severe oxalate poisoning in livestock. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"A-halogeton"
],
"scope": "Species-specific",
"note": "",
"id": "halogeton-1"
},
{
"label": "Plants & habitat",
"sources": [
"A-halogeton"
],
"scope": "Species-specific",
"note": "",
"id": "halogeton-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "halogeton-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "halogeton-4"
},
{
"label": "Other animals",
"sources": [
"A-halogeton"
],
"scope": "Species-specific",
"note": "",
"id": "halogeton-5"
},
{
"id": "halogeton-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"halogeton-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"halogeton-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/halogeton.md"
}
---
# Halogeton
*Halogeton glomeratus*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Severe oxalate poisoning in livestock.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf** — Small fleshy cylindrical blue-green leaves cluster along a reddish stem.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Halogeton_glomeratus_(3939415093).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bd/Halogeton_glomeratus_%283939415093%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Sparse branching green plants on open pale disturbed soil.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Halogeton_glomeratus_(3939417023).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a1/Halogeton_glomeratus_%283939417023%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature-plant** — Upright pinkish stems densely covered with pale papery reproductive structures.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Halogeton_glomeratus_(4030266721).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c7/Halogeton_glomeratus_%284030266721%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual of saline disturbed ground with fleshy, narrow leaves ending in a hair-like tip; stems may redden. [A-halogeton](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/halogeton-halogeton-glomeratus/)
## Plants & habitat
Occupies disturbed dry rangeland and saline soils. Prevent seed spread and involve the local weed program. [A-halogeton](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/halogeton-halogeton-glomeratus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Soluble oxalates can cause severe, sometimes fatal poisoning in sheep and cattle. Dry plants remain hazardous; do not assume curing or senescence makes forage safe. [A-halogeton](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/halogeton-halogeton-glomeratus/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **A-halogeton** — [Halogeton (Halogeton glomeratus)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/halogeton-halogeton-glomeratus/), USDA Agricultural Research Service. Accessed 2026-09-07T01:13:59+00:00. Locator: Description; distribution; poisoning; management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=halogeton) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| halogeton-1 | Recognize | Species-specific | A-halogeton | No quantitative safe exposure established here. |
| halogeton-2 | Plants & habitat | Species-specific | A-halogeton | No quantitative safe exposure established here. |
| halogeton-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| halogeton-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| halogeton-5 | Other animals | Species-specific | A-halogeton | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/halogeton/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md
---
{
"id": "hemp-dogbane",
"name": "Hemp dogbane",
"scientific": "Apocynum cannabinum",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Cardiac-glycoside poisoning hazard for people and animals",
"warning_tone": "danger",
"aliases": [
"Indian hemp",
"prairie dogbane"
],
"taxonomy_note": "Not Cannabis. Apocynum androsaemifolium is a different dogbane. Pet signs are explicitly sourced to the ASPCA genus account, not silently transferred from its differently named species page.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-apocynum-cannabinum",
"P-dogbane",
"F-apocynum",
"S27"
],
"description": "Hemp dogbane: Cardiac-glycoside poisoning hazard for people and animals. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-apocynum-cannabinum"
],
"scope": "Species-specific",
"note": "",
"id": "hemp-dogbane-1"
},
{
"label": "People",
"sources": [
"N-apocynum-cannabinum"
],
"scope": "Species-specific",
"note": "",
"id": "hemp-dogbane-2"
},
{
"label": "Dogs & cats",
"sources": [
"P-dogbane"
],
"scope": "Genus-level veterinary evidence",
"note": "",
"id": "hemp-dogbane-3"
},
{
"label": "Other animals",
"sources": [
"F-apocynum"
],
"scope": "Species-specific",
"note": "",
"id": "hemp-dogbane-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-apocynum-cannabinum"
],
"scope": "Species-specific",
"note": "",
"id": "hemp-dogbane-5"
},
{
"label": "Management & timing",
"sources": [
"N-apocynum-cannabinum",
"F-apocynum"
],
"scope": "Management synthesis",
"note": "",
"id": "hemp-dogbane-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 33; Apocynum cannabinum",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Apocynum cannabinum"
},
"source": "content/plants/hemp-dogbane.md"
}
---
# Hemp dogbane
*Apocynum cannabinum*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Cardiac-glycoside poisoning hazard for people and animals.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Not Cannabis. Apocynum androsaemifolium is a different dogbane. Pet signs are explicitly sourced to the ASPCA genus account, not silently transferred from its differently named species page.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**stand** — A dense leafy flowering stand beside a cultivated field.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Apocynum_cannabinum_15-p.bot-apoc.canna-19.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/72/Apocynum_cannabinum_15-p.bot-apoc.canna-19.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Dogbane species and hybrids can overlap. Identification follows the exact source labels; one candidate with an inconsistent flower form was rejected before final selection. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers and leaves** — Clusters of small pale bell-like flowers and green buds above opposite leaves on reddish branches.
Photo: Cbaile19; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Apocynum_cannabinum,_2021-06-11,_Banksville,_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/82/Apocynum_cannabinum%2C_2021-06-11%2C_Banksville%2C_01.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Dogbane species and hybrids can overlap. Identification follows the exact source labels; one candidate with an inconsistent flower form was rejected before final selection. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**pods** — Numerous long slender hanging pods among opposite leaves and reddish branches.
Photo: Michael Wolf; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Apocynum_cannabinum_fruits.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/14/Apocynum_cannabinum_fruits.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Dogbane species and hybrids can overlap. Identification follows the exact source labels; one candidate with an inconsistent flower form was rejected before final selection. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A branching perennial with opposite oval leaves, milky sap, small greenish-white flowers and narrow paired pods containing silky-haired seed. [N-apocynum-cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/)
## People
All parts are highly toxic if ingested. Reported effects include gastrointestinal illness, weakness and severe heart effects; sap can also blister skin. [N-apocynum-cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/)
## Dogs & cats
ASPCA lists Apocynum species as toxic to dogs and cats. Its group-level signs include weakness, diarrhea and a slow heart rate. Contact a veterinarian promptly after suspected ingestion. [P-dogbane](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/dogbane-hemp)
*Evidence scope: Genus-level veterinary evidence.*
## Other animals
The Forest Service reports livestock poisoning, including potentially fatal effects. Low palatability does not make contaminated forage safe. [F-apocynum](https://research.fs.usda.gov/feis/species-reviews/apocan)
## Plants & habitat
It spreads underground and can form persistent colonies. It also supplies nectar and habitat for insects. Native status and ecological value coexist with a serious ingestion hazard. [N-apocynum-cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/)
## Management & timing
Plan control of the whole colony and prevent access by grazing or chewing animals. Protect skin from sap while handling. [N-apocynum-cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/) [F-apocynum](https://research.fs.usda.gov/feis/species-reviews/apocan)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-apocynum-cannabinum** — [Apocynum cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **P-dogbane** — [Dogbane hemp](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/dogbane-hemp), ASPCA Animal Poison Control. Accessed 2026-09-07T02:26:10+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **F-apocynum** — [Hemp dogbane](https://research.fs.usda.gov/feis/species-reviews/apocan), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:50+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hemp-dogbane) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 33; Apocynum cannabinum. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Not Cannabis. Apocynum androsaemifolium is a different dogbane. Pet signs are explicitly sourced to the ASPCA genus account, not silently transferred from its differently named species page.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hemp-dogbane-1 | Identification | Species-specific | N-apocynum-cannabinum | No quantitative safe exposure established here. |
| hemp-dogbane-2 | People | Species-specific | N-apocynum-cannabinum | No quantitative safe exposure established here. |
| hemp-dogbane-3 | Dogs & cats | Genus-level veterinary evidence | P-dogbane | No quantitative safe exposure established here. |
| hemp-dogbane-4 | Other animals | Species-specific | F-apocynum | No quantitative safe exposure established here. |
| hemp-dogbane-5 | Plants & habitat | Species-specific | N-apocynum-cannabinum | No quantitative safe exposure established here. |
| hemp-dogbane-6 | Management & timing | Management synthesis | N-apocynum-cannabinum, F-apocynum | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/henbit/index.md
---
{
"id": "henbit",
"name": "Henbit",
"scientific": "Lamium amplexicaule",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "An early-flowering weed with useful nectar",
"warning_tone": "caution",
"aliases": [
"henbit deadnettle"
],
"taxonomy_note": "Henbit differs from purple deadnettle (Lamium purpureum), whose upper leaves have stalks. Neither common name establishes a relationship to stinging nettles.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-lamium-amplexicaule",
"S27"
],
"description": "Henbit: An early-flowering weed with useful nectar. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-lamium-amplexicaule"
],
"scope": "Species-specific",
"note": "",
"id": "henbit-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "henbit-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "henbit-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "henbit-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-lamium-amplexicaule"
],
"scope": "Species-specific",
"note": "",
"id": "henbit-5"
},
{
"label": "Management & timing",
"sources": [
"N-lamium-amplexicaule"
],
"scope": "Management inference from life cycle",
"note": "",
"id": "henbit-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"henbit-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"henbit-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"henbit-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 60; Lamium amplexicaule",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Lamium amplexicaule"
},
"source": "content/plants/henbit.md"
}
---
# Henbit
*Lamium amplexicaule*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **An early-flowering weed with useful nectar.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Henbit differs from purple deadnettle (Lamium purpureum), whose upper leaves have stalks. Neither common name establishes a relationship to stinging nettles.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Several long purple tubular flowers rising from a whorl of rounded clasping leaves.
Photo: Patrick Alexander from Las Cruces, NM; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Lamium_amplexicaule_-_Flickr_-_aspidoscelis_(1).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/be/Lamium_amplexicaule_-_Flickr_-_aspidoscelis_%281%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source species. Clasping upper leaves and long tubular flowers are visible, but other Lamium species should still be compared using a botanical key. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower detail** — Two open pink-purple tubular flowers with spotted lower lips above a leafy whorl.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Lamium_amplexicaule_kz06.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2e/Lamium_amplexicaule_kz06.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source species. Clasping upper leaves and long tubular flowers are visible, but other Lamium species should still be compared using a botanical key. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves and buds** — Rounded, scalloped upper leaves clasping stems around clusters of buds and small flowers.
Photo: Patrick Alexander from Las Cruces, NM; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Lamium_amplexicaule_-_Flickr_-_aspidoscelis_(2).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/be/Lamium_amplexicaule_-_Flickr_-_aspidoscelis_%282%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source species. Clasping upper leaves and long tubular flowers are visible, but other Lamium species should still be compared using a botanical key. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A cool-season annual with square stems, rounded scalloped leaves and tubular purple-pink flowers. Upper leaves clasp the stem; lower leaves have stalks. [N-lamium-amplexicaule](https://plants.ces.ncsu.edu/plants/lamium-amplexicaule/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It can spread in moist disturbed soil by seed and rooting stems. Its early flowers supply nectar and pollen to bees. [N-lamium-amplexicaule](https://plants.ces.ncsu.edu/plants/lamium-amplexicaule/)
## Management & timing
Where unwanted, remove young plants and rooting stems before seed production. The shallow root system and annual life cycle make seed prevention useful. [N-lamium-amplexicaule](https://plants.ces.ncsu.edu/plants/lamium-amplexicaule/)
*Evidence scope: Management inference from life cycle.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-lamium-amplexicaule** — [Lamium amplexicaule](https://plants.ces.ncsu.edu/plants/lamium-amplexicaule/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=henbit) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 60; Lamium amplexicaule. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Henbit differs from purple deadnettle (Lamium purpureum), whose upper leaves have stalks. Neither common name establishes a relationship to stinging nettles.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| henbit-1 | Identification | Species-specific | N-lamium-amplexicaule | No quantitative safe exposure established here. |
| henbit-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| henbit-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| henbit-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| henbit-5 | Plants & habitat | Species-specific | N-lamium-amplexicaule | No quantitative safe exposure established here. |
| henbit-6 | Management & timing | Management inference from life cycle | N-lamium-amplexicaule | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/henbit/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/henbit/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/henbit/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/index.md
---
{
"id": "hoary-cress",
"name": "Hoary cress",
"scientific": "Lepidium draba",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Spreading roots; possible livestock poisoning",
"warning_tone": "caution",
"aliases": [
"whitetop",
"Cardaria draba"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"J-hoary-cress",
"S27",
"Fremont-list-definitions"
],
"description": "Hoary cress: Spreading roots; possible livestock poisoning. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-hoary-cress"
],
"scope": "Species-specific",
"note": "",
"id": "hoary-cress-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-hoary-cress"
],
"scope": "Species-specific",
"note": "",
"id": "hoary-cress-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hoary-cress-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hoary-cress-4"
},
{
"label": "Other animals",
"sources": [
"J-hoary-cress"
],
"scope": "Species-specific",
"note": "",
"id": "hoary-cress-5"
},
{
"id": "hoary-cress-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"hoary-cress-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"hoary-cress-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/hoary-cress.md"
}
---
# Hoary cress
*Lepidium draba*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spreading roots; possible livestock poisoning.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A dense patch of whitetop in bloom, with broad white flower clusters above green leaves.
Photo: Katrin Schneider / korina.info; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Korina_2015-05-21_Lepidium_draba_1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/75/Korina_2015-05-21_Lepidium_draba_1.jpg). Source-identified photograph with visual consistency check Pfeilkresse ( Lepidium draba ) Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Source photographic plate showing a four-petaled white whitetop flower from above and from the side, with a 5 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Lepidium_draba_(subsp._draba)_sl15.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/38/Lepidium_draba_%28subsp._draba%29_sl15.jpg). Source-identified photograph with visual consistency check Flower Taxonym: Lepidium draba (subsp. draba) ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Steinberg near Niederhollabrunn, district Korneuburg, Lower Austria - ca. 375 m a.s.l. Habitat: wayside Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**young leaves and buds** — Young whitetop shoot with broad, somewhat toothed leaves around compact green flower buds.
Photo: Fabricio Cardenas; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:20180325_-_C%C3%A9ret_-_Lepidium_draba.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7b/20180325_-_C%C3%A9ret_-_Lepidium_draba.jpg). Source-identified photograph with visual consistency check Lepidium draba (brocoli sauvage) dans les environs de Céret. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Blue-green leaves with clasping upper bases and crowded clusters of small white, four-petaled flowers. [J-hoary-cress](https://www.jeffco.us/2436/Hoary-Cress)
## Plants & habitat
Creeping roots create dense colonies in fields and disturbed ground. Root pieces can regrow after pulling or cultivation. [J-hoary-cress](https://www.jeffco.us/2436/Hoary-Cress)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The county reports possible livestock poisoning and advises against grazing as a simple control method. [J-hoary-cress](https://www.jeffco.us/2436/Hoary-Cress)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-hoary-cress** — [Hoary Cress](https://www.jeffco.us/2436/Hoary-Cress), Jefferson County, Colorado. Accessed 2026-09-07T01:08:56+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hoary-cress) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hoary-cress-1 | Recognize | Species-specific | J-hoary-cress | No quantitative safe exposure established here. |
| hoary-cress-2 | Plants & habitat | Species-specific | J-hoary-cress | No quantitative safe exposure established here. |
| hoary-cress-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hoary-cress-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hoary-cress-5 | Other animals | Species-specific | J-hoary-cress | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md
---
{
"id": "horseweed",
"name": "Horseweed",
"scientific": "Erigeron canadensis",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Fast windborne spread; some populations resist herbicides",
"warning_tone": "caution",
"aliases": [
"Conyza canadensis",
"marestail"
],
"taxonomy_note": "CNHP treats Conyza canadensis as native in its 2020 assessment and records historical disagreement over western nativity. NC State uses Erigeron canadensis. Horseweed is also a common name for unrelated plants.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-erigeron-canadensis",
"S27"
],
"description": "Horseweed: Fast windborne spread; some populations resist herbicides. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-erigeron-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "horseweed-1"
},
{
"label": "People",
"sources": [
"N-erigeron-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "horseweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "horseweed-3"
},
{
"label": "Other animals",
"sources": [
"N-erigeron-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "horseweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-erigeron-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "horseweed-5"
},
{
"label": "Management & timing",
"sources": [
"N-erigeron-canadensis"
],
"scope": "Species-specific",
"note": "",
"id": "horseweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"horseweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"horseweed-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 46; Conyza canadensis",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Conyza canadensis"
},
"source": "content/plants/horseweed.md"
}
---
# Horseweed
*Erigeron canadensis*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Fast windborne spread; some populations resist herbicides.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** CNHP treats Conyza canadensis as native in its 2020 assessment and records historical disagreement over western nativity. NC State uses Erigeron canadensis. Horseweed is also a common name for unrelated plants.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**mature habit** — A tall upright stem topped by a broad, finely branched pale mature head cluster.
Photo: Enrico Blasutto; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Erigeron_canadensis_ENBLA01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fb/Erigeron_canadensis_ENBLA01.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source file titles use Erigeron canadensis and source descriptions use its synonym Conyza canadensis. Similar horseweed species were not substituted; source names are preserved. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowering stem** — A tall branched flowering stem with many small heads and numerous narrow leaves below.
Photo: Enrico Blasutto; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Erigeron_canadensis_ENBLA04.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c0/Erigeron_canadensis_ENBLA04.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source file titles use Erigeron canadensis and source descriptions use its synonym Conyza canadensis. Similar horseweed species were not substituted; source names are preserved. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**seed head** — Close view of a small mature head releasing fine pale pappus hairs, beside green and spent heads.
Photo: Enrico Blasutto; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Erigeron_canadensis_ENBLA07.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/19/Erigeron_canadensis_ENBLA07.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source file titles use Erigeron canadensis and source descriptions use its synonym Conyza canadensis. Similar horseweed species were not substituted; source names are preserved. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
Starts as a hairy leaf rosette, then rises into a narrow upright plant with many small pale flower heads near the top. Leaves become smaller up the stem. [N-erigeron-canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/)
## People
NC State reports mucosal irritation. Avoid ingestion; the source does not establish a safe amount. [N-erigeron-canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The same source reports mucosal irritation in livestock. It gives no validated safe feeding rate. [N-erigeron-canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/)
## Plants & habitat
A prolific disturbance weed with windborne seed; flowers and hollow stems also support native bees. Glyphosate resistance is documented in some populations, not assumed for every Colorado patch. [N-erigeron-canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/)
## Management & timing
Remove plants completely before seed release; broken stems can regrow. Seek local advice when repeated treatment fails. [N-erigeron-canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-erigeron-canadensis** — [Erigeron canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=horseweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 46; Conyza canadensis. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
CNHP treats Conyza canadensis as native in its 2020 assessment and records historical disagreement over western nativity. NC State uses Erigeron canadensis. Horseweed is also a common name for unrelated plants.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| horseweed-1 | Identification | Species-specific | N-erigeron-canadensis | No quantitative safe exposure established here. |
| horseweed-2 | People | Species-specific | N-erigeron-canadensis | No quantitative safe exposure established here. |
| horseweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| horseweed-4 | Other animals | Species-specific | N-erigeron-canadensis | No quantitative safe exposure established here. |
| horseweed-5 | Plants & habitat | Species-specific | N-erigeron-canadensis | No quantitative safe exposure established here. |
| horseweed-6 | Management & timing | Species-specific | N-erigeron-canadensis | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/horseweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md
---
{
"id": "houndstongue",
"name": "Houndstongue",
"scientific": "Cynoglossum officinale",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-houndstongue"
],
"warning": "Toxic to livestock",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"J-houndstongue",
"Fremont-list-definitions"
],
"description": "Houndstongue: Toxic to livestock. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-houndstongue"
],
"scope": "Species-specific",
"note": "",
"id": "houndstongue-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-houndstongue"
],
"scope": "Species-specific",
"note": "",
"id": "houndstongue-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific human ingestion effects were not established in the reviewed county source.",
"id": "houndstongue-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "houndstongue-4"
},
{
"label": "Other animals",
"sources": [
"J-houndstongue"
],
"scope": "Species-specific",
"note": "",
"id": "houndstongue-5"
},
{
"id": "houndstongue-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"houndstongue-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"houndstongue-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/houndstongue.md"
}
---
# Houndstongue
*Cynoglossum officinale*
**Colorado noxious weed · List B — Stop the spread.** [J-houndstongue](https://www.jeffco.us/2414/Houndstongue)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Toxic to livestock.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Upright leafy flowering plant with broad lance-shaped foliage and branched upper flower stems.
Photo: Bernd Haynold; [CC BY 2.5](https://creativecommons.org/licenses/by/2.5); [source record](https://commons.wikimedia.org/wiki/File:Cynoglossum_officinale_190506.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a6/Cynoglossum_officinale_190506.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Small dark red-purple flowers in branching clusters above broad green leaves.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cynoglossum_officinale_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b2/Cynoglossum_officinale_RF.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit** — Green bristly nutlets developing among dark purple five-lobed flowers on hairy stems.
Photo: Antti Bilund; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Cynoglossum_officinale_flowers_fruits_close_up_AB.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/58/Cynoglossum_officinale_flowers_fruits_close_up_AB.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Hairy leaves form a rosette before stems carry small reddish-purple flowers. A biennial or short-lived perennial. [J-houndstongue](https://www.jeffco.us/2414/Houndstongue)
## Plants & habitat
Introduced from Eurasia; spreads by seed in disturbed rangelands and pastures. Prevent seed production and monitor rosettes. [J-houndstongue](https://www.jeffco.us/2414/Houndstongue)
## People
Species-specific human ingestion effects were not established in the reviewed county source. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Contains alkaloids poisonous to livestock. The county explicitly advises against grazing it. [J-houndstongue](https://www.jeffco.us/2414/Houndstongue)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-houndstongue** — [Houndstongue](https://www.jeffco.us/2414/Houndstongue), Jefferson County, Colorado. Accessed 2026-09-07T00:27:22+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=houndstongue) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| houndstongue-1 | Recognize | Species-specific | J-houndstongue | No quantitative exposure threshold established here. |
| houndstongue-2 | Plants & habitat | Species-specific | J-houndstongue | No quantitative exposure threshold established here. |
| houndstongue-3 | People | Review limitation | Review limitation | Species-specific human ingestion effects were not established in the reviewed county source. |
| houndstongue-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| houndstongue-5 | Other animals | Species-specific | J-houndstongue | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/index.md
---
{
"id": "hybrid-knapweed",
"name": "Spotted × diffuse knapweed hybrid",
"scientific": "Centaurea × psammogena",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Hybrid identification needs expert review",
"warning_tone": "caution",
"aliases": [
"hybrid knapweed"
],
"taxonomy_note": "The source explains chromosome and subspecies differences in the parents and uncertainty in older identifications. The photographs come from a community research-grade Colorado observation, not genetic testing. No parent-species poisoning syndrome is assumed for the hybrid.",
"source_ids": [
"CO-rules-2025",
"F-knapweed",
"S27",
"Fremont-list-definitions"
],
"description": "Spotted × diffuse knapweed hybrid: Hybrid identification needs expert review. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "hybrid-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-knapweed",
"CO-rules-2025"
],
"scope": "Species-specific",
"note": "",
"id": "hybrid-knapweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-knapweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-knapweed-5"
},
{
"id": "hybrid-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"hybrid-knapweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"hybrid-knapweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"hybrid-knapweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/hybrid-knapweed.md"
}
---
# Spotted × diffuse knapweed hybrid
*Centaurea × psammogena*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Hybrid identification needs expert review.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The source explains chromosome and subspecies differences in the parents and uncertainty in older identifications. The photographs come from a community research-grade Colorado observation, not genetic testing. No parent-species poisoning syndrome is assumed for the hybrid.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**head and bracts** — A pink-purple hybrid-knapweed head and several buds held beside branching stems; the source identifies this Littleton, Colorado plant as Centaurea × psammogena.
Photo: Tyler; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/230868147); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/409969172/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification is explicit; hybrid status has not been independently confirmed genetically. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A widely branched hybrid-knapweed plant with scattered pink-purple heads in dry vegetation; source location is Littleton, Colorado.
Photo: Tyler; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/230868147); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/409969216/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification is explicit; hybrid status has not been independently confirmed genetically. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Close view of a pale pink and purple hybrid-knapweed flower head; source location is Littleton, Colorado.
Photo: Tyler; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/230868147); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/409969094/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification is explicit; hybrid status has not been independently confirmed genetically. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A fertile hybrid of diffuse and spotted knapweed, often misidentified. A mix of parental appearance does not by itself prove hybrid identity. [F-knapweed](https://research.fs.usda.gov/feis/species-reviews/cendif)
## Plants & habitat
The Forest Service records the hybrid in Colorado. Colorado lists the hybrid separately, so do not discard suspect plants from a weed survey simply because they do not fit a parent’s key. [F-knapweed](https://research.fs.usda.gov/feis/species-reviews/cendif) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-knapweed** — [Diffuse knapweed and hybrid taxonomy](https://research.fs.usda.gov/feis/species-reviews/cendif), USDA Forest Service Fire Effects Information System. Accessed 2026-09-07T01:21:11+00:00. Locator: Species identity, description, ecology and exposure evidence.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hybrid-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The source explains chromosome and subspecies differences in the parents and uncertainty in older identifications. The photographs come from a community research-grade Colorado observation, not genetic testing. No parent-species poisoning syndrome is assumed for the hybrid.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hybrid-knapweed-1 | Recognize | Species-specific | F-knapweed | No quantitative safe exposure established here. |
| hybrid-knapweed-2 | Plants & habitat | Species-specific | F-knapweed, CO-rules-2025 | No quantitative safe exposure established here. |
| hybrid-knapweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hybrid-knapweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hybrid-knapweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/index.md
---
{
"id": "hybrid-toadflax",
"name": "Yellow × Dalmatian toadflax hybrid",
"scientific": "Linaria vulgaris × Linaria dalmatica",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Variable hybrid; persistent spreading roots",
"warning_tone": "caution",
"aliases": [
"hybrid toadflax"
],
"taxonomy_note": "Reference photos are identified hybrids in a USDA Forest Service manual. The third, flower-detail image is small because the original source is only 176 × 329 pixels; it has not been enlarged to imply more detail.",
"source_ids": [
"CO-rules-2025",
"F-toadflaxes",
"S27",
"Fremont-list-definitions"
],
"description": "Yellow × Dalmatian toadflax hybrid: Variable hybrid; persistent spreading roots. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-toadflaxes"
],
"scope": "Species-specific",
"note": "",
"id": "hybrid-toadflax-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-toadflaxes"
],
"scope": "Hybrid-group evidence; performance varies",
"note": "",
"id": "hybrid-toadflax-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-toadflax-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-toadflax-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hybrid-toadflax-5"
},
{
"id": "hybrid-toadflax-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"hybrid-toadflax-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"hybrid-toadflax-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"hybrid-toadflax-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/hybrid-toadflax.md"
}
---
# Yellow × Dalmatian toadflax hybrid
*Linaria vulgaris × Linaria dalmatica*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Variable hybrid; persistent spreading roots.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Reference photos are identified hybrids in a USDA Forest Service manual. The third, flower-detail image is small because the original source is only 176 × 329 pixels; it has not been enlarged to imply more detail.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf and shoot variation** — Several fresh hybrid-toadflax shoots with variable, relatively broad leaves, photographed against a white background.
Photo: Sharlene E. Sing, USDA Forest Service, Rocky Mountain Research Station; [Public domain (U.S. federal employee work)](https://research.fs.usda.gov/sites/default/files/2024-05/srs-SRS-AuthorsGuide-2024.pdf); [source record](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf#page=37); [original image](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf). Explicit federal publication identification of the requested hybrid Printed page 28 explicitly defines hybrid toadflax as Linaria vulgaris × L. dalmatica / L. dalmatica × L. vulgaris. The caption to Figure 22b explicitly identifies the selected panel as hybrid toadflax. Hybrid identity follows the publication; no independent genetic determination was performed. None: original embedded JPEG byte stream extracted from PDF, not a rendered or cropped page. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**narrower foliage and flowers** — Hybrid-toadflax shoots with narrower leaves, including a yellow-flowering stem and an uprooted stem, photographed against white.
Photo: Sharlene E. Sing, USDA Forest Service, Rocky Mountain Research Station; [Public domain (U.S. federal employee work)](https://research.fs.usda.gov/sites/default/files/2024-05/srs-SRS-AuthorsGuide-2024.pdf); [source record](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf#page=37); [original image](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf). Explicit federal publication identification of the requested hybrid Printed page 28 explicitly defines hybrid toadflax as Linaria vulgaris × L. dalmatica / L. dalmatica × L. vulgaris. The caption to Figure 22c explicitly identifies the selected panel as hybrid toadflax. Hybrid identity follows the publication; no independent genetic determination was performed. None: original embedded JPEG byte stream extracted from PDF, not a rendered or cropped page. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Yellow hybrid-toadflax flowers with insects visible on the flowers; a small source photograph.
Photo: Sharlene E. Sing, USDA Forest Service, Rocky Mountain Research Station; [Public domain (U.S. federal employee work)](https://research.fs.usda.gov/sites/default/files/2024-05/srs-SRS-AuthorsGuide-2024.pdf); [source record](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf#page=39); [original image](https://www.fs.usda.gov/rm/pubs_journals/2016/rmrs_2016_sing_s001.pdf). Explicit federal publication identification of the requested hybrid Printed page 28 explicitly defines hybrid toadflax as Linaria vulgaris × L. dalmatica / L. dalmatica × L. vulgaris. The caption to Figure 24e explicitly identifies the selected panel as hybrid toadflax. Hybrid identity follows the publication; no independent genetic determination was performed. The only independently photographed federal hybrid flower panel located in this guide is 176×329 pixels. It is retained as a clearly flagged small reference; it does not meet the requested 960–1280-pixel target and was not upscaled. None: original embedded JPEG byte stream extracted from PDF, not a rendered or cropped page. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow spurred flowers and variable leaves may combine parental traits; leaf width and flower color alone cannot confirm a hybrid. [F-toadflaxes](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf)
## Plants & habitat
Perennial hybrids spread through root buds and seeds. The federal guide reports vigorous growth and competitive potential in disturbed habitats. [F-toadflaxes](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf)
*Evidence scope: Hybrid-group evidence; performance varies.*
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-toadflaxes** — [Biology and Biological Control of Dalmatian and Yellow Toadflax](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf), USDA Forest Service. Accessed 2026-09-07T01:19:10+00:00. Locator: Species or hybrid identity, description and ecology.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hybrid-toadflax) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Reference photos are identified hybrids in a USDA Forest Service manual. The third, flower-detail image is small because the original source is only 176 × 329 pixels; it has not been enlarged to imply more detail.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hybrid-toadflax-1 | Recognize | Species-specific | F-toadflaxes | No quantitative safe exposure established here. |
| hybrid-toadflax-2 | Plants & habitat | Hybrid-group evidence; performance varies | F-toadflaxes | No quantitative safe exposure established here. |
| hybrid-toadflax-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hybrid-toadflax-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hybrid-toadflax-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md
---
{
"id": "hydrilla",
"name": "Hydrilla",
"scientific": "Hydrilla verticillata",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Dense aquatic growth; wildlife disease association",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Separate hydrilla from native waterweeds using a botanical key. Disease association is not proof that every plant or waterbody is toxic.",
"source_ids": [
"CO-rules-2025",
"N-hydrilla-verticillata",
"S27",
"Fremont-list-definitions"
],
"description": "Hydrilla: Dense aquatic growth; wildlife disease association. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-hydrilla-verticillata"
],
"scope": "Species-specific",
"note": "",
"id": "hydrilla-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-hydrilla-verticillata"
],
"scope": "Species-specific",
"note": "",
"id": "hydrilla-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hydrilla-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "hydrilla-4"
},
{
"label": "Other animals",
"sources": [
"N-hydrilla-verticillata"
],
"scope": "Species-specific",
"note": "",
"id": "hydrilla-5"
},
{
"id": "hydrilla-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"hydrilla-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"hydrilla-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"hydrilla-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/hydrilla.md"
}
---
# Hydrilla
*Hydrilla verticillata*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Dense aquatic growth; wildlife disease association.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Separate hydrilla from native waterweeds using a botanical key. Disease association is not proof that every plant or waterbody is toxic.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf-whorl detail** — A wet stem tip with short leaves in whorls and toothed leaf margins.
Photo: Stanislav Murashkin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/175178376); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/304416621/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other submerged waterweeds can look similar. Identification follows the sources; the close view shows toothed leaves in whorls, while the whole-shoot photographs show overall structure. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**whole shoots** — Several long, branching shoots laid against a plain background, showing spaced leaf whorls and lower root-like structures.
Photo: Darkmax; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Hydrilla_Verticillata_3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3d/Hydrilla_Verticillata_3.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other submerged waterweeds can look similar. Identification follows the sources; the close view shows toothed leaves in whorls, while the whole-shoot photographs show overall structure. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**whole stem** — A long hydrilla stem held above a stream, showing repeated dense leaf whorls.
Photo: Alex Abair; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Hydrilla_verticillata_54198908.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/47/Hydrilla_verticillata_54198908.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Other submerged waterweeds can look similar. Identification follows the sources; the close view shows toothed leaves in whorls, while the whole-shoot photographs show overall structure. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A submerged plant with whorls of small, toothed leaves, often with teeth beneath the midrib. It can form dense surface growth. [N-hydrilla-verticillata](https://plants.ces.ncsu.edu/plants/hydrilla-verticillata/)
## Plants & habitat
Fragments and overwintering tubers support persistent infestations. Dense growth displaces native aquatic vegetation. [N-hydrilla-verticillata](https://plants.ces.ncsu.edu/plants/hydrilla-verticillata/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
NC State reports an association with bacteria involved in a neurological disease of waterfowl. The plant’s presence alone does not establish toxin exposure at a particular Colorado waterbody. [N-hydrilla-verticillata](https://plants.ces.ncsu.edu/plants/hydrilla-verticillata/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-hydrilla-verticillata** — [hydrilla verticillata — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hydrilla-verticillata/), NC State Extension. Accessed 2026-09-07T01:04:52+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=hydrilla) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Separate hydrilla from native waterweeds using a botanical key. Disease association is not proof that every plant or waterbody is toxic.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| hydrilla-1 | Recognize | Species-specific | N-hydrilla-verticillata | No quantitative safe exposure established here. |
| hydrilla-2 | Plants & habitat | Species-specific | N-hydrilla-verticillata | No quantitative safe exposure established here. |
| hydrilla-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hydrilla-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| hydrilla-5 | Other animals | Species-specific | N-hydrilla-verticillata | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md
---
{
"id": "japanese-knotweed",
"name": "Japanese knotweed",
"scientific": "Reynoutria japonica",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Root and stem fragments regrow",
"warning_tone": "caution",
"aliases": [
"Fallopia japonica",
"Polygonum cuspidatum"
],
"taxonomy_note": "Colorado’s rule uses Fallopia japonica. Giant and Bohemian knotweeds need separate identification; broad leaves and bamboo-like stems are insufficient to distinguish them.",
"source_ids": [
"CO-rules-2025",
"N-reynoutria-japonica",
"S27",
"Fremont-list-definitions"
],
"description": "Japanese knotweed: Root and stem fragments regrow. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-reynoutria-japonica"
],
"scope": "Species-specific",
"note": "",
"id": "japanese-knotweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-reynoutria-japonica"
],
"scope": "Species-specific",
"note": "",
"id": "japanese-knotweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "japanese-knotweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "japanese-knotweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "japanese-knotweed-5"
},
{
"id": "japanese-knotweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"japanese-knotweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"japanese-knotweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"japanese-knotweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/japanese-knotweed.md"
}
---
# Japanese knotweed
*Reynoutria japonica*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Root and stem fragments regrow.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado’s rule uses Fallopia japonica. Giant and Bohemian knotweeds need separate identification; broad leaves and bamboo-like stems are insufficient to distinguish them.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaves and flowers** — Broad pointed leaves and pale flower clusters viewed against the light.
Photo: Michael Gasperl ( Migas ); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Reynoutria_japonica_(Blaetter-Biene).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/ed/Reynoutria_japonica_%28Blaetter-Biene%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Japanese, giant, and Bohemian knotweeds can overlap in overall appearance. These photographs retain the source identification; a field determination should use mature leaf bases, underside hairs, and other diagnostic characters. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering habit** — A dense leafy stand with abundant pale flower clusters.
Photo: User:BotBln; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Reynoutria_japonica_Habitus_BotGardBln0906.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d0/Reynoutria_japonica_Habitus_BotGardBln0906.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Japanese, giant, and Bohemian knotweeds can overlap in overall appearance. These photographs retain the source identification; a field determination should use mature leaf bases, underside hairs, and other diagnostic characters. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of small cream-white flowers spaced along a slender flowering branch.
Photo: Udo Schmidt from Deutschland; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Reynoutria_japonica_Houtt._Syn.-_Fallopia_japonica_Houtt_(9221546461).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/af/Reynoutria_japonica_Houtt._Syn.-_Fallopia_japonica_Houtt_%289221546461%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Japanese, giant, and Bohemian knotweeds can overlap in overall appearance. These photographs retain the source identification; a field determination should use mature leaf bases, underside hairs, and other diagnostic characters. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Tall hollow, jointed stems carry alternate, broad leaves with generally flattened bases and small, pale flower clusters. [N-reynoutria-japonica](https://plants.ces.ncsu.edu/plants/reynoutria-japonica/)
## Plants & habitat
Rhizomes form dense stands and cut stems can root in wet conditions. Growth can displace streambank vegetation; avoid moving contaminated soil or plant pieces. [N-reynoutria-japonica](https://plants.ces.ncsu.edu/plants/reynoutria-japonica/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-reynoutria-japonica** — [reynoutria japonica — Plant Toolbox](https://plants.ces.ncsu.edu/plants/reynoutria-japonica/), NC State Extension. Accessed 2026-09-07T01:04:52+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=japanese-knotweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Colorado’s rule uses Fallopia japonica. Giant and Bohemian knotweeds need separate identification; broad leaves and bamboo-like stems are insufficient to distinguish them.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| japanese-knotweed-1 | Recognize | Species-specific | N-reynoutria-japonica | No quantitative safe exposure established here. |
| japanese-knotweed-2 | Plants & habitat | Species-specific | N-reynoutria-japonica | No quantitative safe exposure established here. |
| japanese-knotweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| japanese-knotweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| japanese-knotweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md
---
{
"id": "jimsonweed",
"name": "Jimsonweed",
"scientific": "Datura stramonium",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Serious poisoning risk to people and animals",
"warning_tone": "danger",
"aliases": [
"thorn apple"
],
"taxonomy_note": "This is Datura stramonium, not a generic profile for every Datura or Brugmansia. Photograph identification does not establish a safe exposure.",
"source_ids": [
"CO-rules-2025",
"N-datura-stramonium",
"C-routt-guide",
"S27"
],
"description": "Jimsonweed: Serious poisoning risk to people and animals. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-datura-stramonium"
],
"scope": "Species-specific",
"note": "",
"id": "jimsonweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-routt-guide"
],
"scope": "Species-specific",
"note": "",
"id": "jimsonweed-2"
},
{
"label": "People",
"sources": [
"N-datura-stramonium"
],
"scope": "Species-specific",
"note": "",
"id": "jimsonweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-datura-stramonium"
],
"scope": "Species-specific",
"note": "",
"id": "jimsonweed-4"
},
{
"label": "Other animals",
"sources": [
"N-datura-stramonium"
],
"scope": "Species-specific",
"note": "",
"id": "jimsonweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/jimsonweed.md"
}
---
# Jimsonweed
*Datura stramonium*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Serious poisoning risk to people and animals.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is Datura stramonium, not a generic profile for every Datura or Brugmansia. Photograph identification does not establish a safe exposure.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Bushy plant with coarsely toothed broad leaves and upright white flowers.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Datura_stramonium_001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4d/Datura_stramonium_001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Large white funnel-shaped flower with pointed lobes above angular toothed leaves.
Photo: Isidre blanc; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:DATURA_STRAMONIUM_-_GUIXERS_-_IB-615.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d1/DATURA_STRAMONIUM_-_GUIXERS_-_IB-615.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit** — Sectioned unripe spiny capsules reveal pale seeds and internal chambers.
Photo: Joozwa; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Datura_stramonium_unripe_fruit.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e6/Datura_stramonium_unripe_fruit.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A coarse annual with toothed leaves, upright trumpet-shaped flowers and prickly seed capsules. [N-datura-stramonium](https://plants.ces.ncsu.edu/plants/datura-stramonium/)
## Plants & habitat
A disturbed-ground weed included in Routt County’s guide. Seed contamination is a concern around animal areas. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
## People
All parts contain toxic tropane alkaloids. Ingestion can cause delirium, convulsions, coma or death; suspected ingestion needs urgent professional help. [N-datura-stramonium](https://plants.ces.ncsu.edu/plants/datura-stramonium/)
## Dogs & cats
NC State flags both dogs and cats. Keep pets from chewing any part, including seeds; suspected ingestion warrants prompt veterinary contact. [N-datura-stramonium](https://plants.ces.ncsu.edu/plants/datura-stramonium/)
## Other animals
Livestock poisoning is also documented. Do not allow access to contaminated feed or plants. [N-datura-stramonium](https://plants.ces.ncsu.edu/plants/datura-stramonium/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-datura-stramonium** — [datura stramonium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/datura-stramonium/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **C-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=jimsonweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is Datura stramonium, not a generic profile for every Datura or Brugmansia. Photograph identification does not establish a safe exposure.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| jimsonweed-1 | Recognize | Species-specific | N-datura-stramonium | No quantitative safe exposure established here. |
| jimsonweed-2 | Plants & habitat | Species-specific | C-routt-guide | No quantitative safe exposure established here. |
| jimsonweed-3 | People | Species-specific | N-datura-stramonium | No quantitative safe exposure established here. |
| jimsonweed-4 | Dogs & cats | Species-specific | N-datura-stramonium | No quantitative safe exposure established here. |
| jimsonweed-5 | Other animals | Species-specific | N-datura-stramonium | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md
---
{
"id": "johnsongrass",
"name": "Johnsongrass",
"scientific": "Sorghum halepense",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Livestock cyanide risk; added fire fuel",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-sorghum-halepense",
"S27",
"Fremont-list-definitions"
],
"description": "Johnsongrass: Livestock cyanide risk; added fire fuel. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-sorghum-halepense"
],
"scope": "Species-specific",
"note": "",
"id": "johnsongrass-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-sorghum-halepense"
],
"scope": "Species-specific",
"note": "",
"id": "johnsongrass-2"
},
{
"label": "People",
"sources": [
"N-sorghum-halepense"
],
"scope": "Species-specific",
"note": "",
"id": "johnsongrass-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "johnsongrass-4"
},
{
"label": "Other animals",
"sources": [
"N-sorghum-halepense"
],
"scope": "Species-specific",
"note": "",
"id": "johnsongrass-5"
},
{
"id": "johnsongrass-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"johnsongrass-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/johnsongrass.md"
}
---
# Johnsongrass
*Sorghum halepense*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Livestock cyanide risk; added fire fuel.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — Close view of grass spikelets with dangling reddish anthers.
Photo: Jim Conrad; [Public domain](https://commons.wikimedia.org/wiki/File:Sorghum_halepense-flowers.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Sorghum_halepense-flowers.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f5/Sorghum_halepense-flowers.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Long flat green leaf blades with conspicuous pale midribs.
Photo: Rsberzerker; [Public domain](https://commons.wikimedia.org/wiki/File:Johnsongrass.JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Johnsongrass.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/28/Johnsongrass.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Tall leafy grass clump with open branching panicles above long arching leaves.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Sorghum_halepense_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/23/Sorghum_halepense_sl1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A tall perennial grass with broad blades, pale midribs and a large, open seedhead. [N-sorghum-halepense](https://plants.ces.ncsu.edu/plants/sorghum-halepense/)
## Plants & habitat
Rhizomes and seed form dense colonies. Productive stands can add fine fuels and promote fire spread. [N-sorghum-halepense](https://plants.ces.ncsu.edu/plants/sorghum-halepense/)
## People
Pollen can trigger hay fever. This is not a substitute for grain sorghum. [N-sorghum-halepense](https://plants.ces.ncsu.edu/plants/sorghum-halepense/)
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Young growth and foliage stressed by frost or hot, dry weather can contain harmful cyanide levels for cattle and horses. Obtain livestock and forage-testing advice before use. [N-sorghum-halepense](https://plants.ces.ncsu.edu/plants/sorghum-halepense/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-sorghum-halepense** — [sorghum halepense — Plant Toolbox](https://plants.ces.ncsu.edu/plants/sorghum-halepense/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=johnsongrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| johnsongrass-1 | Recognize | Species-specific | N-sorghum-halepense | No quantitative safe exposure established here. |
| johnsongrass-2 | Plants & habitat | Species-specific | N-sorghum-halepense | No quantitative safe exposure established here. |
| johnsongrass-3 | People | Species-specific | N-sorghum-halepense | No quantitative safe exposure established here. |
| johnsongrass-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| johnsongrass-5 | Other animals | Species-specific | N-sorghum-halepense | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/index.md
---
{
"id": "jointed-goatgrass",
"name": "Jointed goatgrass",
"scientific": "Aegilops cylindrica",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Wheat-field and rangeland seed spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"J-jointed-goatgrass",
"S27",
"Fremont-list-definitions"
],
"description": "Jointed goatgrass: Wheat-field and rangeland seed spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-jointed-goatgrass"
],
"scope": "Species-specific",
"note": "",
"id": "jointed-goatgrass-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-jointed-goatgrass"
],
"scope": "Species-specific",
"note": "",
"id": "jointed-goatgrass-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "jointed-goatgrass-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "jointed-goatgrass-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "jointed-goatgrass-5"
},
{
"id": "jointed-goatgrass-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"jointed-goatgrass-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"jointed-goatgrass-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"jointed-goatgrass-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/jointed-goatgrass.md"
}
---
# Jointed goatgrass
*Aegilops cylindrica*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Wheat-field and rangeland seed spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**green flowering stems** — A stand of slender green jointed-goatgrass stems with narrow cylindrical spikes.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Aegilops_cylindrica_sl55.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0d/Aegilops_cylindrica_sl55.jpg). Source-identified photograph with visual consistency check Spikes Taxonym: Aegilops cylindrica ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: next to Stammersdorf, Vienna-Floridsdorf - ca. 160 m a.s.l. Habitat: grassy stripe next to windbreak strip Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**spikelet detail** — Source photographic plate showing jointed goatgrass spikelets and their attachment to the spike axis, with a 5 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Aegilops_cylindrica_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/de/Aegilops_cylindrica_sl1.jpg). Source-identified photograph with visual consistency check Spikelets Taxonym: Aegilops cylindrica ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 ; det. Gergely Király 2015-06-07 Location: Veszprém County, Hungary - ca. 200 m a.s.l. Habitat: slope Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**maturing stand** — Slender jointed-goatgrass stems and cylindrical spikes turning reddish brown in a dense stand.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Aegilops_cylindrica_(3822187792).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/dd/Aegilops_cylindrica_%283822187792%29.jpg). Source-identified photograph with visual consistency check Jointed goatgrass has a very distinctive cylindrical inflorescence where the internode and the adjacent spikelet shatter (disarticulate) as a unit. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual grass with narrow leaves and a cylindrical seed spike that looks like stacked segments. Leaf margins and collars bear hairs. [J-jointed-goatgrass](https://www.jeffco.us/2413/Jointed-Goatgrass)
## Plants & habitat
Occurs in wheat fields, rangeland and disturbed corridors. Spreads by seed, so clean equipment and prevent seed maturation. [J-jointed-goatgrass](https://www.jeffco.us/2413/Jointed-Goatgrass)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-jointed-goatgrass** — [Jointed Goatgrass](https://www.jeffco.us/2413/Jointed-Goatgrass), Jefferson County, Colorado. Accessed 2026-09-07T01:08:57+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=jointed-goatgrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| jointed-goatgrass-1 | Recognize | Species-specific | J-jointed-goatgrass | No quantitative safe exposure established here. |
| jointed-goatgrass-2 | Plants & habitat | Species-specific | J-jointed-goatgrass | No quantitative safe exposure established here. |
| jointed-goatgrass-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| jointed-goatgrass-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| jointed-goatgrass-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md
---
{
"id": "kochia",
"name": "Kochia",
"scientific": "Bassia scoparia",
"category": "invasive",
"status": "Introduced annual weed; not designated on the reviewed Colorado A/B/C lists",
"status_sources": [
"C-tumbleweeds",
"CO-rules-2025"
],
"warning": "Tumbling seed spread; livestock poisoning risk",
"warning_tone": "danger",
"aliases": [
"Kochia scoparia",
"burning bush",
"summer cypress",
"tumbleweed"
],
"taxonomy_note": "Bassia scoparia is also published as Kochia scoparia. It is distinct from Russian thistle and from the woody ornamental Euonymus alatus, also called burning bush.",
"source_ids": [
"C-tumbleweeds",
"CO-rules-2025",
"S27",
"K-kochia"
],
"description": "Kochia: Tumbling seed spread; livestock poisoning risk. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-tumbleweeds"
],
"scope": "Species-specific",
"note": "",
"id": "kochia-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-tumbleweeds"
],
"scope": "Species-specific",
"note": "",
"id": "kochia-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "kochia-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "kochia-4"
},
{
"label": "Other animals",
"sources": [
"C-tumbleweeds"
],
"scope": "Species-specific",
"note": "",
"id": "kochia-5"
},
{
"id": "kochia-taxonomy",
"label": "Taxonomy",
"scope": "Species-specific",
"sources": [
"K-kochia"
],
"note": "Synonym mapping"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"kochia-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"kochia-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/kochia.md"
}
---
# Kochia
*Bassia scoparia*
**Introduced annual weed; not designated on the reviewed Colorado A/B/C lists.** [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Tumbling seed spread; livestock poisoning risk.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Bassia scoparia is also published as Kochia scoparia. It is distinct from Russian thistle and from the woody ornamental Euonymus alatus, also called burning bush.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright bushy green plant with many narrow leaves on densely branched stems.
Photo: WildBoar; [Public domain](https://commons.wikimedia.org/wiki/File:Kochia_scoparia_01.JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Kochia_scoparia_01.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/7/74/Kochia_scoparia_01.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Kochia scoparia is a synonym of Bassia scoparia. Habit can differ between feral plants and cultivated compact forms; no cultivar or subspecies determination is made from these photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering-branches** — Slender branching stems bear narrow leaves and small inconspicuous reproductive clusters at the leaf axils.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Kochia_scoparia_(5129371229).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/90/Kochia_scoparia_%285129371229%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Kochia scoparia is a synonym of Bassia scoparia. Habit can differ between feral plants and cultivated compact forms; no cultivar or subspecies determination is made from these photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**dried-form** — Detached dry brown rounded plants rest on pale bare soil.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Bassia_scoparia_sl16.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7a/Bassia_scoparia_sl16.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Kochia scoparia is a synonym of Bassia scoparia. Habit can differ between feral plants and cultivated compact forms; no cultivar or subspecies determination is made from these photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Taxonomy
Cornell uses Bassia scoparia and identifies Kochia scoparia as its synonym. [K-kochia](https://cals.cornell.edu/weed-science/weed-profiles/kochia)
## Recognize
A bushy annual with narrow, alternate, hairy leaves and small inconspicuous flowers. Plants may turn reddish and break off at the base when dry. [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/)
## Plants & habitat
Colonizes disturbed yards, roadsides and pastures. New seedlings can emerge over a long season; preventing seed set requires follow-up. Dry plants can tumble and scatter seeds. [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
CSU reports several toxic compounds, including nitrates and oxalates, that can poison cattle and sheep. Maturity and drought can increase the risk. Obtain veterinary and forage-testing advice before grazing or feeding contaminated material. [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-tumbleweeds** — [Identification and Management of Kochia and Russian Thistle](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/), Colorado State University Extension. Accessed 2026-09-07T00:57:25+00:00. Locator: Weed Description; Livestock Poisonings; Integrated Weed Management.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
- **K-kochia** — [Kochia](https://cals.cornell.edu/weed-science/weed-profiles/kochia), Cornell University College of Agriculture and Life Sciences. Accessed 2026-09-07T01:16:19+00:00. Locator: taxonomy.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=kochia) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Bassia scoparia is also published as Kochia scoparia. It is distinct from Russian thistle and from the woody ornamental Euonymus alatus, also called burning bush.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| kochia-1 | Recognize | Species-specific | C-tumbleweeds | No quantitative safe exposure established here. |
| kochia-2 | Plants & habitat | Species-specific | C-tumbleweeds | No quantitative safe exposure established here. |
| kochia-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| kochia-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| kochia-5 | Other animals | Species-specific | C-tumbleweeds | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/kochia/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/index.md
---
{
"id": "lambs-ear",
"name": "Lamb’s-ear",
"scientific": "Stachys byzantina",
"category": "xeriscape",
"status": "Introduced low-water perennial",
"status_sources": [
"N-stachys-byzantina"
],
"warning": "Can spread; pet evidence gap",
"warning_tone": "caution",
"aliases": [
"lamb's-ear",
"lamb's ears"
],
"taxonomy_note": "Cultivars differ in flowering and leaf size. Deer resistance does not demonstrate safety for pets.",
"source_ids": [
"N-stachys-byzantina"
],
"description": "Lamb’s-ear: Can spread; pet evidence gap. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-stachys-byzantina"
],
"scope": "Species-specific",
"note": "",
"id": "lambs-ear-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-stachys-byzantina"
],
"scope": "Species-specific",
"note": "",
"id": "lambs-ear-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "A recommendation for sensory gardens is not a human ingestion-safety assessment.",
"id": "lambs-ear-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "lambs-ear-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "lambs-ear-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"lambs-ear-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"lambs-ear-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"lambs-ear-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/lambs-ear.md"
}
---
# Lamb’s-ear
*Stachys byzantina*
**Introduced low-water perennial.** [N-stachys-byzantina](https://plants.ces.ncsu.edu/plants/stachys-byzantina/)
> **Can spread; pet evidence gap.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Cultivars differ in flowering and leaf size. Deer resistance does not demonstrate safety for pets.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**leaf detail** — Magnified lamb's-ear leaf tip densely covered in silvery hairs, with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Stachys_byzantina_sl28.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4c/Stachys_byzantina_sl28.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**young foliage** — Close view of a soft, woolly shoot tip and unfolding pale leaves.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Stachys_byzantina_2020-05-20_8717.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bb/Stachys_byzantina_2020-05-20_8717.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Several upright woolly flower spikes bearing pink-purple flowers above fuzzy elongated leaves.
Photo: Cbaile19; [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Stachys_byzantina,_2015-06-02,_Beechview,_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8c/Stachys_byzantina%2C_2015-06-02%2C_Beechview%2C_01.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Thick, soft, woolly silver leaves form low rosettes; flowering forms carry purplish-pink spikes. [N-stachys-byzantina](https://plants.ces.ncsu.edu/plants/stachys-byzantina/)
## Plants & habitat
Stems root where they touch soil. It can spread aggressively in favorable conditions; divide when needed and avoid wet soil. [N-stachys-byzantina](https://plants.ces.ncsu.edu/plants/stachys-byzantina/)
## People
A recommendation for sensory gardens is not a human ingestion-safety assessment. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-stachys-byzantina** — [Stachys byzantina — Plant Toolbox](https://plants.ces.ncsu.edu/plants/stachys-byzantina/), NC State Extension. Accessed 2026-09-07T00:23:58+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=lambs-ear) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Cultivars differ in flowering and leaf size. Deer resistance does not demonstrate safety for pets.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| lambs-ear-1 | Recognize | Species-specific | N-stachys-byzantina | No quantitative exposure threshold established here. |
| lambs-ear-2 | Plants & habitat | Species-specific | N-stachys-byzantina | No quantitative exposure threshold established here. |
| lambs-ear-3 | People | Review limitation | Review limitation | A recommendation for sensory gardens is not a human ingestion-safety assessment. |
| lambs-ear-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| lambs-ear-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/index.md
---
{
"id": "large-crabgrass",
"name": "Large crabgrass",
"scientific": "Digitaria sanguinalis",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Fast seed production in thin lawns",
"warning_tone": "caution",
"aliases": [
"crabgrass",
"hairy crabgrass"
],
"taxonomy_note": "One source photograph is labeled Digitaria sanguinalis subsp. pectiniformis; that label is preserved, without asserting its occurrence in Colorado.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-digitaria-sanguinalis",
"C-descriptions",
"S27"
],
"description": "Large crabgrass: Fast seed production in thin lawns. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-digitaria-sanguinalis",
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "large-crabgrass-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "large-crabgrass-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "large-crabgrass-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "large-crabgrass-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-digitaria-sanguinalis"
],
"scope": "Species-specific",
"note": "",
"id": "large-crabgrass-5"
},
{
"label": "Management & timing",
"sources": [
"N-digitaria-sanguinalis"
],
"scope": "Species-specific",
"note": "",
"id": "large-crabgrass-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"large-crabgrass-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"large-crabgrass-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"large-crabgrass-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 49; Digitaria sanguinalis",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Digitaria sanguinalis"
},
"source": "content/plants/large-crabgrass.md"
}
---
# Large crabgrass
*Digitaria sanguinalis*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Fast seed production in thin lawns.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** One source photograph is labeled Digitaria sanguinalis subsp. pectiniformis; that label is preserved, without asserting its occurrence in Colorado.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A low spreading grass clump with green leaf blades and long radiating stems on bare soil.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Harig_vingergras_plant_(Digitaria_sanguinalis).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fa/Harig_vingergras_plant_%28Digitaria_sanguinalis%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified D. sanguinalis. The inflorescence photo is explicitly labeled D. sanguinalis subsp. pectiniformis and retains that source wording. Similar crabgrasses require detailed hair, ligule, and spikelet characters for an unknown specimen; these references do not determine a Colorado specimen’s subspecies. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-collar** — Several photographed leaf bases showing membranous ligules and conspicuous long hairs.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Harig_vingergras_ligula_(Digitaria_sanguinalis).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6e/Harig_vingergras_ligula_%28Digitaria_sanguinalis%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified D. sanguinalis. The inflorescence photo is explicitly labeled D. sanguinalis subsp. pectiniformis and retains that source wording. Similar crabgrasses require detailed hair, ligule, and spikelet characters for an unknown specimen; these references do not determine a Colorado specimen’s subspecies. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**inflorescence** — Several slender finger-like flower spikes radiate from the top of a grass stem against a blue sky.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Digitaria_sanguinalis_subsp._pectiniformis_sl18.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/42/Digitaria_sanguinalis_subsp._pectiniformis_sl18.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified D. sanguinalis. The inflorescence photo is explicitly labeled D. sanguinalis subsp. pectiniformis and retains that source wording. Similar crabgrasses require detailed hair, ligule, and spikelet characters for an unknown specimen; these references do not determine a Colorado specimen’s subspecies. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A summer annual grass with sprawling stems that root at joints, hairy leaf bases and fingerlike seedhead branches. This profile covers large crabgrass; the common name also includes other Digitaria species. [N-digitaria-sanguinalis](https://plants.ces.ncsu.edu/plants/digitaria-sanguinalis/) [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It colonizes disturbed soil and lawns. Its ability to root along spreading stems helps it occupy bare patches. [N-digitaria-sanguinalis](https://plants.ces.ncsu.edu/plants/digitaria-sanguinalis/)
## Management & timing
Remove seedlings before extensive rooting and seed production. Mulch garden beds and maintain dense turf; frost kills the annual plant, but surviving seeds can start another generation. [N-digitaria-sanguinalis](https://plants.ces.ncsu.edu/plants/digitaria-sanguinalis/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-digitaria-sanguinalis** — [Digitaria sanguinalis](https://plants.ces.ncsu.edu/plants/digitaria-sanguinalis/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=large-crabgrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 49; Digitaria sanguinalis. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| large-crabgrass-1 | Identification | Species-specific | N-digitaria-sanguinalis, C-descriptions | No quantitative safe exposure established here. |
| large-crabgrass-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| large-crabgrass-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| large-crabgrass-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| large-crabgrass-5 | Plants & habitat | Species-specific | N-digitaria-sanguinalis | No quantitative safe exposure established here. |
| large-crabgrass-6 | Management & timing | Species-specific | N-digitaria-sanguinalis | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md
---
{
"id": "leafy-spurge",
"name": "Leafy spurge",
"scientific": "Euphorbia esula",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-leafy-spurge"
],
"warning": "Irritating sap; eye injury risk",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Colorado references use Euphorbia esula. Leafy-spurge taxonomy can involve closely related taxa; this profile does not resolve every population or hybrid.",
"source_ids": [
"J-leafy-spurge",
"N-euphorbia-esula",
"Fremont-list-definitions"
],
"description": "Leafy spurge: Irritating sap; eye injury risk. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-euphorbia-esula"
],
"scope": "Species-specific",
"note": "",
"id": "leafy-spurge-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-leafy-spurge"
],
"scope": "Species-specific",
"note": "",
"id": "leafy-spurge-2"
},
{
"label": "People",
"sources": [
"N-euphorbia-esula"
],
"scope": "Species-specific",
"note": "",
"id": "leafy-spurge-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-euphorbia-esula"
],
"scope": "Species-specific",
"note": "",
"id": "leafy-spurge-4"
},
{
"label": "Other animals",
"sources": [
"J-leafy-spurge"
],
"scope": "Animal-group-specific management evidence",
"note": "",
"id": "leafy-spurge-5"
},
{
"id": "leafy-spurge-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/leafy-spurge.md"
}
---
# Leafy spurge
*Euphorbia esula*
**Colorado noxious weed · List B — Stop the spread.** [J-leafy-spurge](https://www.jeffco.us/2406/Leafy-Spurge)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Irritating sap; eye injury risk.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado references use Euphorbia esula. Leafy-spurge taxonomy can involve closely related taxa; this profile does not resolve every population or hybrid.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Dense upright leafy stems topped with yellow-green flower clusters.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_esula_001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/8/81/Euphorbia_esula_001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Leafy-spurge taxonomy is complex. North American invasive leafy spurge is frequently assigned to Euphorbia virgata or an E. esula aggregate. These are source-identified E. esula reference photographs, including a leaf explicitly labeled E. esula sensu stricto; do not assume they prove a Colorado plant is E. esula in the narrow sense. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Close view of yellow-green bracts, cyathia, and rounded developing capsules.
Photo: Kristian Peters -- Fabelfroh 13:02, 3 November 2005 (UTC); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_esula_bluete.jpeg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3e/Euphorbia_esula_bluete.jpeg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Leafy-spurge taxonomy is complex. North American invasive leafy spurge is frequently assigned to Euphorbia virgata or an E. esula aggregate. These are source-identified E. esula reference photographs, including a leaf explicitly labeled E. esula sensu stricto; do not assume they prove a Colorado plant is E. esula in the narrow sense. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Magnified photographed leaf tip with its broad rounded apex and scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_esula_(s._str.)_sl8.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f8/Euphorbia_esula_%28s._str.%29_sl8.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Leafy-spurge taxonomy is complex. North American invasive leafy spurge is frequently assigned to Euphorbia virgata or an E. esula aggregate. These are source-identified E. esula reference photographs, including a leaf explicitly labeled E. esula sensu stricto; do not assume they prove a Colorado plant is E. esula in the narrow sense. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Upright stems, narrow leaves and yellow-green bracts surrounding small flowers. All parts contain milky latex. Do not break stems just to test for sap. [N-euphorbia-esula](https://plants.ces.ncsu.edu/plants/euphorbia-esula/)
## Plants & habitat
Spreads by roots and seed, forming persistent patches that displace vegetation. Root fragments can regrow. [J-leafy-spurge](https://www.jeffco.us/2406/Leafy-Spurge)
## People
Sap can cause dermatitis and potentially permanent eye damage; ingestion can blister the mouth. Protect skin and eyes. [N-euphorbia-esula](https://plants.ces.ncsu.edu/plants/euphorbia-esula/)
## Dogs & cats
NC State flags both dogs and cats and advises keeping pets away. A pet-specific toxic dose is not provided. [N-euphorbia-esula](https://plants.ces.ncsu.edu/plants/euphorbia-esula/)
## Other animals
Cattle can suffer lesions and digestive irritation. Managed sheep or goat grazing is a specialist control method, not evidence that unrestricted consumption is safe for all animals. [J-leafy-spurge](https://www.jeffco.us/2406/Leafy-Spurge)
*Evidence scope: Animal-group-specific management evidence.*
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-leafy-spurge** — [Leafy Spurge](https://www.jeffco.us/2406/Leafy-Spurge), Jefferson County, Colorado. Accessed 2026-09-07T00:27:23+00:00. Locator: Description, impacts, Colorado list designation, management.
- **N-euphorbia-esula** — [Euphorbia esula — Plant Toolbox](https://plants.ces.ncsu.edu/plants/euphorbia-esula/), NC State Extension. Accessed 2026-09-07T00:24:01+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=leafy-spurge) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Colorado references use Euphorbia esula. Leafy-spurge taxonomy can involve closely related taxa; this profile does not resolve every population or hybrid.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| leafy-spurge-1 | Recognize | Species-specific | N-euphorbia-esula | No quantitative exposure threshold established here. |
| leafy-spurge-2 | Plants & habitat | Species-specific | J-leafy-spurge | No quantitative exposure threshold established here. |
| leafy-spurge-3 | People | Species-specific | N-euphorbia-esula | No quantitative exposure threshold established here. |
| leafy-spurge-4 | Dogs & cats | Species-specific | N-euphorbia-esula | No quantitative exposure threshold established here. |
| leafy-spurge-5 | Other animals | Animal-group-specific management evidence | J-leafy-spurge | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/index.md
---
{
"id": "lewis-blue-flax",
"name": "Lewis blue flax",
"scientific": "Linum lewisii",
"category": "xeriscape",
"status": "Colorado native; low-water garden plant",
"status_sources": [
"C-perennials"
],
"warning": "Ingestion and contact concerns",
"warning_tone": "caution",
"aliases": [
"blue flax",
"western blue flax"
],
"taxonomy_note": "Use Linum lewisii records, not L. perenne or culinary flax L. usitatissimum. The source’s food-use language is not adopted as preparation advice.",
"source_ids": [
"C-perennials",
"N-linum-lewisii"
],
"description": "Lewis blue flax: Ingestion and contact concerns. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-linum-lewisii"
],
"scope": "Species-specific",
"note": "",
"id": "lewis-blue-flax-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-linum-lewisii"
],
"scope": "Species-specific",
"note": "",
"id": "lewis-blue-flax-2"
},
{
"label": "People",
"sources": [
"N-linum-lewisii"
],
"scope": "Species-specific",
"note": "",
"id": "lewis-blue-flax-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "lewis-blue-flax-4"
},
{
"label": "Other animals",
"sources": [
"N-linum-lewisii"
],
"scope": "Species-specific livestock warning",
"note": "",
"id": "lewis-blue-flax-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"lewis-blue-flax-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"lewis-blue-flax-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/lewis-blue-flax.md"
}
---
# Lewis blue flax
*Linum lewisii*
**Colorado native; low-water garden plant.** [C-perennials](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/)
> **Ingestion and contact concerns.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Use Linum lewisii records, not L. perenne or culinary flax L. usitatissimum. The source’s food-use language is not adopted as preparation advice.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**leaf and stem** — Close view of slender narrow leaves along a green flax stem.
Photo: Walter Siegmund (talk); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Linum_lewisii_9746.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/0/03/Linum_lewisii_9746.JPG). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Blue five-petaled flax flowers with pale veins and yellow centers, on a slender flowering stem.
Photo: NPS / Jacob W. Frank; [Public domain](https://commons.wikimedia.org/wiki/File:Blue_Flax_-_Linum_lewisii_(37066946561).jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Blue_Flax_-_Linum_lewisii_(37066946561).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/18/Blue_Flax_-_Linum_lewisii_%2837066946561%29.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Airy clump of thin stems carrying numerous blue flowers in dry grassland.
Photo: Skoch3; [CC BY-SA 3.0](http://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Linum_lewisii,_blue_flax,_Albuquerque.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d0/Linum_lewisii%2C_blue_flax%2C_Albuquerque.JPG). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Delicate five-petaled blue flowers above narrow leaves on slender stems. [N-linum-lewisii](https://plants.ces.ncsu.edu/plants/linum-lewisii/)
## Plants & habitat
A short-lived perennial that reseeds freely; reduce seed set if many volunteers are unwanted. It needs sun and drainage. [N-linum-lewisii](https://plants.ces.ncsu.edu/plants/linum-lewisii/)
## People
The source flags cyanogenic glycosides and contact dermatitis. This guide does not establish edible preparations or safe doses. [N-linum-lewisii](https://plants.ces.ncsu.edu/plants/linum-lewisii/)
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Large intake is reported as a concern for cattle and sheep, with potentially severe respiratory effects. Do not assume ornamental flax is suitable feed. [N-linum-lewisii](https://plants.ces.ncsu.edu/plants/linum-lewisii/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-perennials** — [Native Herbaceous Perennials for Colorado Landscapes](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/), Colorado State University Extension. Accessed 2026-09-07T00:27:17+00:00. Locator: Description, distribution, hazards, management; see claim locator.
- **N-linum-lewisii** — [Linum lewisii — Plant Toolbox](https://plants.ces.ncsu.edu/plants/linum-lewisii/), NC State Extension. Accessed 2026-09-07T00:23:59+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=lewis-blue-flax) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use Linum lewisii records, not L. perenne or culinary flax L. usitatissimum. The source’s food-use language is not adopted as preparation advice.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| lewis-blue-flax-1 | Recognize | Species-specific | N-linum-lewisii | No quantitative exposure threshold established here. |
| lewis-blue-flax-2 | Plants & habitat | Species-specific | N-linum-lewisii | No quantitative exposure threshold established here. |
| lewis-blue-flax-3 | People | Species-specific | N-linum-lewisii | No quantitative exposure threshold established here. |
| lewis-blue-flax-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| lewis-blue-flax-5 | Other animals | Species-specific livestock warning | N-linum-lewisii | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md
---
{
"id": "low-larkspur",
"name": "Low larkspur",
"scientific": "Delphinium nuttallianum",
"category": "native",
"status": "Native Colorado wildflower; grazing and ingestion hazard",
"status_sources": [
"C-routt-guide"
],
"warning": "Serious livestock and pet poisoning hazard",
"warning_tone": "danger",
"aliases": [
"Delphinium nelsonii"
],
"taxonomy_note": "This profile focuses on Delphinium nuttallianum. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.",
"source_ids": [
"C-routt-guide",
"ARS-larkspur",
"A-larkspur",
"S27"
],
"description": "Low larkspur: Serious livestock and pet poisoning hazard. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"ARS-larkspur"
],
"scope": "Larkspur-group morphology; use a species key",
"note": "",
"id": "low-larkspur-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-routt-guide"
],
"scope": "Species-specific",
"note": "",
"id": "low-larkspur-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "low-larkspur-3"
},
{
"label": "Dogs & cats",
"sources": [
"A-larkspur"
],
"scope": "Genus-level warning; no species-specific pet threshold",
"note": "",
"id": "low-larkspur-4"
},
{
"label": "Other animals",
"sources": [
"ARS-larkspur"
],
"scope": "Larkspur-group evidence",
"note": "",
"id": "low-larkspur-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"low-larkspur-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/low-larkspur.md"
}
---
# Low larkspur
*Delphinium nuttallianum*
**Native Colorado wildflower; grazing and ingestion hazard.** [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
> **Serious livestock and pet poisoning hazard.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This profile focuses on Delphinium nuttallianum. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering patch** — A patch of low blue-flowered larkspur growing among stones and dry leaf litter.
Photo: NPS; [Public domain](https://commons.wikimedia.org/wiki/File:Common_Larkspur_(Delphinium_nuttallianum)_(7ce5a6d0-44a3-4017-b3da-5f52d211f664).jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Common_Larkspur_(Delphinium_nuttallianum)_(7ce5a6d0-44a3-4017-b3da-5f52d211f664).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/de/Common_Larkspur_%28Delphinium_nuttallianum%29_%287ce5a6d0-44a3-4017-b3da-5f52d211f664%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species, Delphinium nuttallianum; Delphinium nuttallii and other larkspurs were not substituted. Similar species require a full botanical key. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of blue sepals, a long spur, and pale central petals.
Photo: Walter Siegmund (talk); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Delphinium_nuttallianum_1824.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a1/Delphinium_nuttallianum_1824.JPG). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species, Delphinium nuttallianum; Delphinium nuttallii and other larkspurs were not substituted. Similar species require a full botanical key. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**whole plant** — A slender flowering stem rising from low divided foliage in mixed grassy vegetation.
Photo: Walter Siegmund (talk); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Delphinium_nuttallianum_4815.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/48/Delphinium_nuttallianum_4815.JPG). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species, Delphinium nuttallianum; Delphinium nuttallii and other larkspurs were not substituted. Similar species require a full botanical key. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Low-growing spring larkspurs have blue spurred flowers and finely divided leaves. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)
*Evidence scope: Larkspur-group morphology; use a species key.*
## Plants & habitat
Routt County records low larkspur in meadows, woodlands and sagebrush slopes. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
ASPCA lists Delphinium species as toxic to dogs and cats. Alkaloids can disrupt nerve and muscle function; suspected ingestion needs prompt veterinary attention. [A-larkspur](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur)
*Evidence scope: Genus-level warning; no species-specific pet threshold.*
## Other animals
Larkspur is a major cattle-poisoning concern. All parts are toxic; severity varies with species, growth stage and conditions. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)
*Evidence scope: Larkspur-group evidence.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **ARS-larkspur** — [Larkspur (Delphinium spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/), USDA Agricultural Research Service. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **A-larkspur** — [Larkspur — Delphinium species](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur), ASPCA Poison Control. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=low-larkspur) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This profile focuses on Delphinium nuttallianum. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| low-larkspur-1 | Recognize | Larkspur-group morphology; use a species key | ARS-larkspur | No quantitative safe exposure established here. |
| low-larkspur-2 | Plants & habitat | Species-specific | C-routt-guide | No quantitative safe exposure established here. |
| low-larkspur-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| low-larkspur-4 | Dogs & cats | Genus-level warning; no species-specific pet threshold | A-larkspur | No quantitative safe exposure established here. |
| low-larkspur-5 | Other animals | Larkspur-group evidence | ARS-larkspur | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/index.md
---
{
"id": "mayweed-chamomile",
"name": "Mayweed chamomile",
"scientific": "Anthemis cotula",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Crop weed with unpleasant-smelling foliage",
"warning_tone": "caution",
"aliases": [
"stinking chamomile",
"dog fennel"
],
"taxonomy_note": "Do not substitute Roman chamomile (Anthemis nobilis / Chamaemelum nobile) toxicology. The retrieved NC State URL described a different plant and was excluded.",
"source_ids": [
"CO-rules-2025",
"UC-mayweed",
"K-chamomiles",
"S27",
"Fremont-list-definitions"
],
"description": "Mayweed chamomile: Crop weed with unpleasant-smelling foliage. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"UC-mayweed"
],
"scope": "Species-specific",
"note": "",
"id": "mayweed-chamomile-1"
},
{
"label": "Plants & habitat",
"sources": [
"UC-mayweed"
],
"scope": "Species-specific",
"note": "",
"id": "mayweed-chamomile-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "mayweed-chamomile-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "mayweed-chamomile-4"
},
{
"label": "Other animals",
"sources": [
"K-chamomiles"
],
"scope": "Species-specific",
"note": "",
"id": "mayweed-chamomile-5"
},
{
"id": "mayweed-chamomile-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"mayweed-chamomile-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"mayweed-chamomile-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/mayweed-chamomile.md"
}
---
# Mayweed chamomile
*Anthemis cotula*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Crop weed with unpleasant-smelling foliage.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Do not substitute Roman chamomile (Anthemis nobilis / Chamaemelum nobile) toxicology. The retrieved NC State URL described a different plant and was excluded.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Mayweed chamomile heads with white rays around raised yellow centers.
Photo: NY State IPM Program at Cornell University from New York, USA; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Anthemis_cotula_-_flowers_(closeup)_(18744849431).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/13/Anthemis_cotula_-_flowers_%28closeup%29_%2818744849431%29.jpg). Source-identified photograph with visual consistency check Mayweed chamomile. For more information on identification and control, visit turfweeds.cals.cornell.edu/plant/identify/157 Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A broad, branching mayweed chamomile plant covered with numerous small white-and-yellow flower heads.
Photo: NY State IPM Program at Cornell University from New York, USA; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Anthemis_cotula_-_whole_plant_(18737495852).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/09/Anthemis_cotula_-_whole_plant_%2818737495852%29.jpg). Source-identified photograph with visual consistency check Mayweed chamomile. For more information on identification and control, visit turfweeds.cals.cornell.edu/plant/identify/157 Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage** — A leafy mayweed chamomile shoot with finely divided green foliage.
Photo: Andrianl; [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Anthemis_cotula_592189591.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d1/Anthemis_cotula_592189591.jpg). Source-identified photograph with visual consistency check Stinking chamomile ( Anthemis cotula ) in New Zealand Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A bushy annual with finely divided leaves, white ray flowers around yellow centers and a strong, unpleasant odor. [UC-mayweed](https://ipm.ucanr.edu/weeds-identification-gallery/mayweed-chamomile/)
## Plants & habitat
Colonizes disturbed ground and agricultural sites; seed production sustains infestations. [UC-mayweed](https://ipm.ucanr.edu/weeds-identification-gallery/mayweed-chamomile/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Cornell reports livestock avoidance and milk taint after consumption. That is not a quantified pet-poisoning assessment. [K-chamomiles](https://cals.cornell.edu/weed-science/weed-profiles/chamomiles)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **UC-mayweed** — [Mayweed chamomile](https://ipm.ucanr.edu/weeds-identification-gallery/mayweed-chamomile/), University of California Statewide IPM. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **K-chamomiles** — [Chamomiles](https://cals.cornell.edu/weed-science/weed-profiles/chamomiles), Cornell University College of Agriculture and Life Sciences. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=mayweed-chamomile) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Do not substitute Roman chamomile (Anthemis nobilis / Chamaemelum nobile) toxicology. The retrieved NC State URL described a different plant and was excluded.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| mayweed-chamomile-1 | Recognize | Species-specific | UC-mayweed | No quantitative safe exposure established here. |
| mayweed-chamomile-2 | Plants & habitat | Species-specific | UC-mayweed | No quantitative safe exposure established here. |
| mayweed-chamomile-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| mayweed-chamomile-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| mayweed-chamomile-5 | Other animals | Species-specific | K-chamomiles | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md
---
{
"id": "meadow-death-camas",
"name": "Meadow death camas",
"scientific": "Toxicoscordion venenosum",
"category": "native",
"status": "Native regional plant; death-camas poisoning hazard",
"status_sources": [
"B-deathcamas",
"C-routt-guide"
],
"warning": "Potentially fatal ingestion; onion-like bulbs",
"warning_tone": "danger",
"aliases": [
"Zigadenus venenosus",
"deathcamas"
],
"taxonomy_note": "Older sources use Zigadenus. T. venenosum includes named varieties; Colorado’s older county guide treats death camas as a group. Images show the species broadly and do not prove a particular variety or county occurrence.",
"source_ids": [
"B-deathcamas",
"C-routt-guide",
"ARS-deathcamas",
"S27"
],
"description": "Meadow death camas: Potentially fatal ingestion; onion-like bulbs. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"ARS-deathcamas"
],
"scope": "Death-camas group morphology",
"note": "",
"id": "meadow-death-camas-1"
},
{
"label": "Plants & habitat",
"sources": [
"B-deathcamas",
"ARS-deathcamas"
],
"scope": "Regional variety and death-camas group",
"note": "",
"id": "meadow-death-camas-2"
},
{
"label": "People",
"sources": [
"ARS-deathcamas"
],
"scope": "Death-camas group including Z. venenosus",
"note": "",
"id": "meadow-death-camas-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "meadow-death-camas-4"
},
{
"label": "Other animals",
"sources": [
"ARS-deathcamas"
],
"scope": "Death-camas group including Z. venenosus",
"note": "",
"id": "meadow-death-camas-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"meadow-death-camas-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/meadow-death-camas.md"
}
---
# Meadow death camas
*Toxicoscordion venenosum*
**Native regional plant; death-camas poisoning hazard.** [B-deathcamas](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Toxicoscordion+venenosum+var.+gramineum) [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
> **Potentially fatal ingestion; onion-like bulbs.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Older sources use Zigadenus. T. venenosum includes named varieties; Colorado’s older county guide treats death camas as a group. Images show the species broadly and do not prove a particular variety or county occurrence.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**whole plant** — An upright cluster of small pale flowers above a basal group of narrow, strap-shaped leaves.
Photo: NPS Photo; [Public domain](https://commons.wikimedia.org/wiki/File:File-Toxicoscordion_venenosum_-_native;_-Alternate_names-_Zigadenus_venenosus,_meadow_death_camas;-Blooms_June_-_August;-All_parts_(644b3042-f25d-4b6f-87d4-9e18f5a40c35).JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:File-Toxicoscordion_venenosum_-_native;_-Alternate_names-_Zigadenus_venenosus,_meadow_death_camas;-Blooms_June_-_August;-All_parts_(644b3042-f25d-4b6f-87d4-9e18f5a40c35).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/0/08/File-Toxicoscordion_venenosum_-_native%3B_-Alternate_names-_Zigadenus_venenosus%2C_meadow_death_camas%3B-Blooms_June_-_August%3B-All_parts_%28644b3042-f25d-4b6f-87d4-9e18f5a40c35%29.JPG). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. The requested name and synonym Zigadenus venenosus are preserved. Other death-camas taxa were not substituted; identification follows the exact scientific source label. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**basal foliage** — Long, narrow basal leaves emerging in a tuft beside the flower stalk, among mixed grassland vegetation.
Photo: paulexcoff; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/46337299); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/73488439/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. The requested name and synonym Zigadenus venenosus are preserved. Other death-camas taxa were not substituted; identification follows the exact scientific source label. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower cluster** — A close view of numerous pale flowers and buds along a compact raceme, held in front of a hand.
Photo: paulexcoff; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/46337299); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/73488405/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. The requested name and synonym Zigadenus venenosus are preserved. Other death-camas taxa were not substituted; identification follows the exact scientific source label. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Death camas has grass-like leaves, underground bulbs and clusters of pale yellow-white flowers. Do not taste a bulb or use onion-like appearance as an edible-plant test. [ARS-deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861)
*Evidence scope: Death-camas group morphology.*
## Plants & habitat
The regional taxon T. venenosum var. gramineum occurs in grassland and pine openings. Death camas is an early-season grazing hazard. [B-deathcamas](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Toxicoscordion+venenosum+var.+gramineum) [ARS-deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861)
*Evidence scope: Regional variety and death-camas group.*
## People
Death-camas bulbs have caused severe and fatal human poisoning. Suspected ingestion requires emergency medical help. [ARS-deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861)
*Evidence scope: Death-camas group including Z. venenosus.*
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
All parts contain poisonous alkaloids; cardiovascular failure can be fatal. Sheep are often affected, but cattle and horses are also at risk. [ARS-deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861)
*Evidence scope: Death-camas group including Z. venenosus.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **B-deathcamas** — [Toxicoscordion venenosum var. gramineum](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Toxicoscordion+venenosum+var.+gramineum), University of Washington Burke Herbarium; Don Knoke and David Giblin. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **C-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **ARS-deathcamas** — [Deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861), USDA Agricultural Research Service. Accessed 2026-09-07T01:37:13+00:00. Locator: Description; toxicity; species group including Zigadenus venenosus.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=meadow-death-camas) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Older sources use Zigadenus. T. venenosum includes named varieties; Colorado’s older county guide treats death camas as a group. Images show the species broadly and do not prove a particular variety or county occurrence.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| meadow-death-camas-1 | Recognize | Death-camas group morphology | ARS-deathcamas | No quantitative safe exposure established here. |
| meadow-death-camas-2 | Plants & habitat | Regional variety and death-camas group | B-deathcamas, ARS-deathcamas | No quantitative safe exposure established here. |
| meadow-death-camas-3 | People | Death-camas group including Z. venenosus | ARS-deathcamas | No quantitative safe exposure established here. |
| meadow-death-camas-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| meadow-death-camas-5 | Other animals | Death-camas group including Z. venenosus | ARS-deathcamas | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/index.md
---
{
"id": "meadow-knapweed",
"name": "Meadow knapweed",
"scientific": "Centaurea × moncktonii",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Outcompetes pasture and meadow plants",
"warning_tone": "caution",
"aliases": [
"Centaurea x moncktonii",
"Centaurea x gerstlaueri"
],
"taxonomy_note": "A hybrid complex associated with C. jacea and C. nigra. Older meadow-knapweed names can represent different taxonomic concepts; records require checking.",
"source_ids": [
"CO-rules-2025",
"WA-meadow-knapweed",
"S27",
"Fremont-list-definitions"
],
"description": "Meadow knapweed: Outcompetes pasture and meadow plants. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-meadow-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "meadow-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-meadow-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "meadow-knapweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "meadow-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "meadow-knapweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "meadow-knapweed-5"
},
{
"id": "meadow-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"meadow-knapweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"meadow-knapweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"meadow-knapweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/meadow-knapweed.md"
}
---
# Meadow knapweed
*Centaurea × moncktonii*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Outcompetes pasture and meadow plants.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** A hybrid complex associated with C. jacea and C. nigra. Older meadow-knapweed names can represent different taxonomic concepts; records require checking.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — A purple flower head among additional buds and spent heads.
Photo: Eric Coombs, Oregon Department of Agriculture, Bugwood.org; [CC BY 3.0 us](https://creativecommons.org/licenses/by/3.0/us/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_%C3%97_moncktonii_5435714.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/11/Centaurea_%C3%97_moncktonii_5435714.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid meadow knapweed (C. jacea × C. nigra). The complex overlaps morphologically; the photographs do not independently establish hybrid ancestry. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**head and bracts** — A flowering head and a spent head held to show the dark involucral bracts.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/14803189); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/22096242/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid meadow knapweed (C. jacea × C. nigra). The complex overlaps morphologically; the photographs do not independently establish hybrid ancestry. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem leaves** — A slender upright stem with narrow, alternate leaves.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/14803189); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/22096211/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. This is the source-identified hybrid meadow knapweed (C. jacea × C. nigra). The complex overlaps morphologically; the photographs do not independently establish hybrid ancestry. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A variable perennial hybrid with mostly undivided leaves and purple to white flowerheads. Brown, papery, fringed flowerhead bracts help distinguish it. [WA-meadow-knapweed](https://www.nwcb.wa.gov/weeds/meadow-knapweed)
## Plants & habitat
Spreads through seed and regrowth from root crowns, replacing desirable forage and native meadow vegetation. [WA-meadow-knapweed](https://www.nwcb.wa.gov/weeds/meadow-knapweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-meadow-knapweed** — [Meadow Knapweed](https://www.nwcb.wa.gov/weeds/meadow-knapweed), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:00+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=meadow-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
A hybrid complex associated with C. jacea and C. nigra. Older meadow-knapweed names can represent different taxonomic concepts; records require checking.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| meadow-knapweed-1 | Recognize | Species-specific | WA-meadow-knapweed | No quantitative safe exposure established here. |
| meadow-knapweed-2 | Plants & habitat | Species-specific | WA-meadow-knapweed | No quantitative safe exposure established here. |
| meadow-knapweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| meadow-knapweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| meadow-knapweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/index.md
---
{
"id": "mediterranean-sage",
"name": "Mediterranean sage",
"scientific": "Salvia aethiopis",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Tumbles and spreads seed through rangeland",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "This is another tumbleweed-forming plant, distinct from Russian sage (Salvia yangii), kochia and Russian thistle. Do not merge their toxicity evidence.",
"source_ids": [
"CO-rules-2025",
"WA-mediterranean-sage",
"S27",
"Fremont-list-definitions"
],
"description": "Mediterranean sage: Tumbles and spreads seed through rangeland. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-mediterranean-sage"
],
"scope": "Species-specific",
"note": "",
"id": "mediterranean-sage-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-mediterranean-sage"
],
"scope": "Species-specific",
"note": "",
"id": "mediterranean-sage-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "mediterranean-sage-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "mediterranean-sage-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "mediterranean-sage-5"
},
{
"id": "mediterranean-sage-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"mediterranean-sage-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"mediterranean-sage-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"mediterranean-sage-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/mediterranean-sage.md"
}
---
# Mediterranean sage
*Salvia aethiopis*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Tumbles and spreads seed through rangeland.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is another tumbleweed-forming plant, distinct from Russian sage (Salvia yangii), kochia and Russian thistle. Do not merge their toxicity evidence.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A pale, branching flowering plant in open grassland.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Salvia_aethiopis_sl13.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/17/Salvia_aethiopis_sl13.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering branches** — White flowers arranged along pale, densely hairy branching stems.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Salvia_aethiopis_sl2.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a8/Salvia_aethiopis_sl2.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**rosette** — A low rosette of broad, wrinkled, woolly leaves.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Salvia_aethiopis_sl68.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/89/Salvia_aethiopis_sl68.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A woolly rosette produces a much-branched, candelabra-like stalk with pale, two-lipped flowers. Upper leaves clasp the square stem. [WA-mediterranean-sage](https://www.nwcb.wa.gov/weeds/mediterranean-sage)
## Plants & habitat
Unpalatable growth can displace forage. Dry flowering stalks detach and tumble, spreading seed. [WA-mediterranean-sage](https://www.nwcb.wa.gov/weeds/mediterranean-sage)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-mediterranean-sage** — [Mediterranean Sage](https://www.nwcb.wa.gov/weeds/mediterranean-sage), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:00+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=mediterranean-sage) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is another tumbleweed-forming plant, distinct from Russian sage (Salvia yangii), kochia and Russian thistle. Do not merge their toxicity evidence.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| mediterranean-sage-1 | Recognize | Species-specific | WA-mediterranean-sage | No quantitative safe exposure established here. |
| mediterranean-sage-2 | Plants & habitat | Species-specific | WA-mediterranean-sage | No quantitative safe exposure established here. |
| mediterranean-sage-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| mediterranean-sage-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| mediterranean-sage-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md
---
{
"id": "medusahead",
"name": "Medusahead",
"scientific": "Taeniatherum caput-medusae",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Barbed awns; persistent fire-promoting thatch",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Similar-looking native grasses exist. Awn and spike structure must be examined before identification or removal.",
"source_ids": [
"CO-rules-2025",
"WA-medusahead",
"S27",
"Fremont-list-definitions"
],
"description": "Medusahead: Barbed awns; persistent fire-promoting thatch. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-medusahead"
],
"scope": "Species-specific",
"note": "",
"id": "medusahead-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-medusahead"
],
"scope": "Species-specific",
"note": "",
"id": "medusahead-2"
},
{
"label": "People",
"sources": [
"WA-medusahead"
],
"scope": "Species-specific",
"note": "",
"id": "medusahead-3"
},
{
"label": "Dogs & cats",
"sources": [
"WA-medusahead"
],
"scope": "Species-specific",
"note": "",
"id": "medusahead-4"
},
{
"label": "Other animals",
"sources": [
"WA-medusahead"
],
"scope": "Species-specific",
"note": "",
"id": "medusahead-5"
},
{
"id": "medusahead-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"medusahead-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/medusahead.md"
}
---
# Medusahead
*Taeniatherum caput-medusae*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Barbed awns; persistent fire-promoting thatch.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Similar-looking native grasses exist. Awn and spike structure must be examined before identification or removal.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**maturing heads** — Dense grass growth with numerous pale, spreading, long-awned heads.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Taeniatherum_caput-medusae_(3872859565).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e4/Taeniatherum_caput-medusae_%283872859565%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**infestation** — A broad straw-coloured stand beside a fence and building.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Taeniatherum_caput-medusae_(3873644920).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d2/Taeniatherum_caput-medusae_%283873644920%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**green heads** — Close view of green spikes with numerous long, slender awns.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Taeniatherum_caput-medusae_(3873651200).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3c/Taeniatherum_caput-medusae_%283873651200%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A winter annual grass with dense seed spikes and long, twisting, barbed awns. [WA-medusahead](https://www.nwcb.wa.gov/weeds/medusahead)
## Plants & habitat
Competes strongly with native vegetation. Slowly decomposing, silica-rich thatch accumulates and can increase fire frequency. [WA-medusahead](https://www.nwcb.wa.gov/weeds/medusahead)
## People
Barbed awns catch on clothing and can scratch; avoid bare-handed handling of mature seedheads. [WA-medusahead](https://www.nwcb.wa.gov/weeds/medusahead)
## Dogs & cats
Awns pose a plausible physical injury concern, but this source is not a species-specific pet case series. Keep pets out of mature seedheads. [WA-medusahead](https://www.nwcb.wa.gov/weeds/medusahead)
## Other animals
Poor forage quality and loss of desirable pasture are documented concerns. An unrestricted feeding-safety threshold is not established. [WA-medusahead](https://www.nwcb.wa.gov/weeds/medusahead)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-medusahead** — [Medusahead](https://www.nwcb.wa.gov/weeds/medusahead), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:00+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=medusahead) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Similar-looking native grasses exist. Awn and spike structure must be examined before identification or removal.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| medusahead-1 | Recognize | Species-specific | WA-medusahead | No quantitative safe exposure established here. |
| medusahead-2 | Plants & habitat | Species-specific | WA-medusahead | No quantitative safe exposure established here. |
| medusahead-3 | People | Species-specific | WA-medusahead | No quantitative safe exposure established here. |
| medusahead-4 | Dogs & cats | Species-specific | WA-medusahead | No quantitative safe exposure established here. |
| medusahead-5 | Other animals | Species-specific | WA-medusahead | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/medusahead/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/index.md
---
{
"id": "moth-mullein",
"name": "Moth mullein",
"scientific": "Verbascum blattaria",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Long-lived seeds sustain infestations",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Unlike common mullein, this species does not have a thickly woolly rosette. Confirm the whole plant, not flower color alone.",
"source_ids": [
"CO-rules-2025",
"J-moth-mullein",
"S27",
"Fremont-list-definitions"
],
"description": "Moth mullein: Long-lived seeds sustain infestations. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-moth-mullein"
],
"scope": "Species-specific",
"note": "",
"id": "moth-mullein-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-moth-mullein"
],
"scope": "Species-specific",
"note": "",
"id": "moth-mullein-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "moth-mullein-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "moth-mullein-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "moth-mullein-5"
},
{
"id": "moth-mullein-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"moth-mullein-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"moth-mullein-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"moth-mullein-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/moth-mullein.md"
}
---
# Moth mullein
*Verbascum blattaria*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Long-lived seeds sustain infestations.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Unlike common mullein, this species does not have a thickly woolly rosette. Confirm the whole plant, not flower color alone.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**capsules** — Round dry moth-mullein capsules on short stalks beside a slender main stem, with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Verbascum_blattaria_sl20.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8c/Verbascum_blattaria_sl20.jpg). Source-identified photograph with visual consistency check Fruits Taxonym: Verbascum blattaria ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Donaugraben west of Stetten, district Korneuburg, Lower Austria - ca. 170 m a.s.l. Habitat: dam Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — A pale yellow moth-mullein flower with a purple center on a slender flowering stem.
Photo: Cbaile19; [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Verbascum_blattaria_(yellow_form),_2023-06-05,_South_Side,_02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3e/Verbascum_blattaria_%28yellow_form%29%2C_2023-06-05%2C_South_Side%2C_02.jpg). Source-identified photograph with visual consistency check Yellow form of Moth Mullein ( Verbascum blattaria ) blooming beside the Monongahela, South Side, Pittsburgh Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Tall, slender moth-mullein flowering stems with broad lower leaves growing in dry grassland.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Verbascum_blattaria_sl25.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a9/Verbascum_blattaria_sl25.jpg). Source-identified photograph with visual consistency check Habitus Taxonym: Verbascum blattaria ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: „Aspelfeld“ 1,5 km SE Alt-Prerau, district Mistelbach, Lower Austria - ca. 180 m a.s.l. Habitat: non-calcareous, sandy fallow land Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A biennial with toothed leaves and loose stalks of white or yellow flowers with purple centers. [J-moth-mullein](https://www.jeffco.us/2402/Moth-Mullein)
## Plants & habitat
A garden escape in pastures and hay fields. Seeds persist, requiring monitoring after removal. [J-moth-mullein](https://www.jeffco.us/2402/Moth-Mullein)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-moth-mullein** — [Moth Mullein](https://www.jeffco.us/2402/Moth-Mullein), Jefferson County, Colorado. Accessed 2026-09-07T01:08:57+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=moth-mullein) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Unlike common mullein, this species does not have a thickly woolly rosette. Confirm the whole plant, not flower color alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| moth-mullein-1 | Recognize | Species-specific | J-moth-mullein | No quantitative safe exposure established here. |
| moth-mullein-2 | Plants & habitat | Species-specific | J-moth-mullein | No quantitative safe exposure established here. |
| moth-mullein-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| moth-mullein-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| moth-mullein-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/index.md
---
{
"id": "musk-thistle",
"name": "Musk thistle",
"scientific": "Carduus nutans",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-musk-thistle"
],
"warning": "Sharp spines; competes with vegetation",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.",
"source_ids": [
"J-musk-thistle",
"Fremont-list-definitions"
],
"description": "Musk thistle: Sharp spines; competes with vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-musk-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "musk-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-musk-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "musk-thistle-2"
},
{
"label": "People",
"sources": [
"J-musk-thistle"
],
"scope": "Physical-risk inference from documented spines",
"note": "",
"id": "musk-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-musk-thistle"
],
"scope": "Physical-risk inference; toxicology gap",
"note": "",
"id": "musk-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed control source does not establish species-specific livestock chemical toxicity.",
"id": "musk-thistle-5"
},
{
"id": "musk-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"musk-thistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"musk-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/musk-thistle.md"
}
---
# Musk thistle
*Carduus nutans*
**Colorado noxious weed · List B — Stop the spread.** [J-musk-thistle](https://www.jeffco.us/2384/Musk-Thistle)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; competes with vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Nodding purple flower head on a curved stalk with pointed involucral bracts.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carduus_nutans_4_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bc/Carduus_nutans_4_RF.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-bud** — Dense deeply lobed spiny foliage surrounding a developing central flower bud.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carduus_nutans_kz20.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/eb/Carduus_nutans_kz20.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Entire low branching flowering thistle showing basal foliage and several pink heads.
Photo: Pierpao; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Carduus_nutans_in_Bosco_Bottari.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/72/Carduus_nutans_in_Bosco_Bottari.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Large, often nodding purple heads and deeply lobed, spiny leaves. Usually a biennial. [J-musk-thistle](https://www.jeffco.us/2384/Musk-Thistle)
## Plants & habitat
Spreads by seed. Preventing seed set is central to control; follow-up is needed as new rosettes emerge. [J-musk-thistle](https://www.jeffco.us/2384/Musk-Thistle)
## People
Spines can puncture skin. Sturdy gloves are a practical precaution when handling; confirm identification before removing a thistle. [J-musk-thistle](https://www.jeffco.us/2384/Musk-Thistle)
*Evidence scope: Physical-risk inference from documented spines.*
## Dogs & cats
Spiny material can injure paws or mouths. Species-specific chemical toxicity is unresolved in this review. [J-musk-thistle](https://www.jeffco.us/2384/Musk-Thistle)
*Evidence scope: Physical-risk inference; toxicology gap.*
## Other animals
The reviewed control source does not establish species-specific livestock chemical toxicity. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-musk-thistle** — [Musk Thistle](https://www.jeffco.us/2384/Musk-Thistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:23+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=musk-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| musk-thistle-1 | Recognize | Species-specific | J-musk-thistle | No quantitative exposure threshold established here. |
| musk-thistle-2 | Plants & habitat | Species-specific | J-musk-thistle | No quantitative exposure threshold established here. |
| musk-thistle-3 | People | Physical-risk inference from documented spines | J-musk-thistle | No quantitative exposure threshold established here. |
| musk-thistle-4 | Dogs & cats | Physical-risk inference; toxicology gap | J-musk-thistle | No quantitative exposure threshold established here. |
| musk-thistle-5 | Other animals | Review limitation | Review limitation | The reviewed control source does not establish species-specific livestock chemical toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md
---
{
"id": "myrtle-spurge",
"name": "Myrtle spurge",
"scientific": "Euphorbia myrsinites",
"category": "invasive",
"status": "Colorado List A — Eradicate",
"status_sources": [
"S14"
],
"warning": "Poisonous · Eye & skin injury",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S14",
"S13",
"S15",
"S27",
"Fremont-list-definitions"
],
"description": "Myrtle spurge: Poisonous · Eye & skin injury. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S13",
"S14",
"S15"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "myrtle-spurge-1"
},
{
"label": "Plants & habitat",
"sources": [
"S13",
"S15",
"S27"
],
"scope": "Species-specific + management guidance",
"note": "Garden exclusion is an editorial recommendation derived from Colorado List A status.",
"reviewed": "2026-09-06",
"id": "myrtle-spurge-2"
},
{
"label": "People",
"sources": [
"S14",
"S15"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "myrtle-spurge-3"
},
{
"label": "Dogs & cats",
"sources": [
"S15"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "myrtle-spurge-4"
},
{
"label": "Other animals",
"sources": [
"S14",
"S15"
],
"scope": "Evidence gap",
"note": "",
"reviewed": "2026-09-06",
"id": "myrtle-spurge-5"
},
{
"id": "myrtle-spurge-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"myrtle-spurge-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/myrtle-spurge.md"
}
---
# Myrtle spurge
*Euphorbia myrsinites*
**Colorado List A — Eradicate.** [S14](https://www.jeffco.us/2364/Myrtle-Spurge)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Poisonous · Eye & skin injury.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Close view of yellow-green bracts and small cup-shaped cyathia.
Photo: Flocci Nivis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:20260411_Euphorbia_myrsinites_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e0/20260411_Euphorbia_myrsinites_01.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Thick blue-green leaves overlap spirally along several trailing stems.
Photo: Qwertzy2; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_myrsinites.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/21/Euphorbia_myrsinites.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Low spreading clump with trailing leafy stems and terminal yellow-green flower clusters.
Photo: Syrio; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_myrsinites_Pr%C3%A0_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bb/Euphorbia_myrsinites_Pr%C3%A0_01.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Trailing fleshy stems, spiraled blue-green leaves, and yellow-green spring bracts. Previously sold as an ornamental. [S13](https://ag.colorado.gov/conservation/noxious-weeds/colorado-noxious-weed-list/myrtle-spurge) [S14](https://www.jeffco.us/2364/Myrtle-Spurge) [S15](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/)
## Plants & habitat
Spreads aggressively by seed. Colorado’s List A goal is eradication; do not select it for a xeriscape garden. [S13](https://ag.colorado.gov/conservation/noxious-weeds/colorado-noxious-weed-list/myrtle-spurge) [S15](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/) [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## People
Sap can cause severe dermatitis and damage the eye’s cornea. All parts are poisonous if eaten; avoid skin and eye contact. [S14](https://www.jeffco.us/2364/Myrtle-Spurge) [S15](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/)
## Dogs & cats
Keep pets away from the poisonous plant and its irritating sap. NC State specifically flags problems for dogs and cats. [S15](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/)
## Other animals
Species-specific livestock effects are not detailed in the references used here. Do not treat that evidence gap as clearance for grazing. [S14](https://www.jeffco.us/2364/Myrtle-Spurge) [S15](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S14** — [Myrtle Spurge](https://www.jeffco.us/2364/Myrtle-Spurge), Jefferson County, Colorado. Accessed 2026-09-07T00:23:54+00:00. Locator: List A designation; General; Plant.
- **S13** — [Myrtle spurge](https://ag.colorado.gov/conservation/noxious-weeds/colorado-noxious-weed-list/myrtle-spurge), Colorado Department of Agriculture. Accessed 2026-09-06. Locator: Species description.
- **S15** — [Euphorbia myrsinites](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/), NC State Extension · Plant Toolbox. Accessed 2026-09-07T00:23:54+00:00. Locator: Description; Poisonous to Humans; Problems.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=myrtle-spurge) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| myrtle-spurge-1 | Recognize | Species-specific | S13, S14, S15 | No quantitative exposure threshold established here. |
| myrtle-spurge-2 | Plants & habitat | Species-specific + management guidance | S13, S15, S27 | Garden exclusion is an editorial recommendation derived from Colorado List A status. |
| myrtle-spurge-3 | People | Species-specific | S14, S15 | No quantitative exposure threshold established here. |
| myrtle-spurge-4 | Dogs & cats | Species-specific | S15 | No quantitative exposure threshold established here. |
| myrtle-spurge-5 | Other animals | Evidence gap | S14, S15 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/index.md
---
{
"id": "narrow-leaved-dalmatian-toadflax",
"name": "Narrow-leaved Dalmatian toadflax",
"scientific": "Linaria genistifolia",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Listed taxon with difficult identification",
"warning_tone": "caution",
"aliases": [
"broomleaf toadflax"
],
"taxonomy_note": "Colorado’s listing name is retained. Drought-stressed L. dalmatica and hybrid toadflaxes can also have narrow leaves. Photographs from Europe show source-identified L. genistifolia; they do not confirm Colorado occurrence. Expert identification is needed before assigning a local plant to this taxon.",
"source_ids": [
"CO-rules-2025",
"F-toadflaxes",
"S27",
"Fremont-list-definitions"
],
"description": "Narrow-leaved Dalmatian toadflax: Listed taxon with difficult identification. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-toadflaxes"
],
"scope": "Species-specific",
"note": "",
"id": "narrow-leaved-dalmatian-toadflax-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-toadflaxes",
"CO-rules-2025"
],
"scope": "Regulatory listing and historical taxonomic uncertainty",
"note": "",
"id": "narrow-leaved-dalmatian-toadflax-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "narrow-leaved-dalmatian-toadflax-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "narrow-leaved-dalmatian-toadflax-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "narrow-leaved-dalmatian-toadflax-5"
},
{
"id": "narrow-leaved-dalmatian-toadflax-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"narrow-leaved-dalmatian-toadflax-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"narrow-leaved-dalmatian-toadflax-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"narrow-leaved-dalmatian-toadflax-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/narrow-leaved-dalmatian-toadflax.md"
}
---
# Narrow-leaved Dalmatian toadflax
*Linaria genistifolia*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Listed taxon with difficult identification.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado’s listing name is retained. Drought-stressed L. dalmatica and hybrid toadflaxes can also have narrow leaves. Photographs from Europe show source-identified L. genistifolia; they do not confirm Colorado occurrence. Expert identification is needed before assigning a local plant to this taxon.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — Side view of yellow toadflax flowers and their long spurs beside developing reproductive structures, with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Linaria_genistifolia_(subsp._genistifolia)_sl31.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/87/Linaria_genistifolia_%28subsp._genistifolia%29_sl31.jpg). Source-identified photograph with visual consistency check Inflorescence Taxonym: Linaria genistifolia (subsp. genistifolia) ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Schmetterlingswiese in Donaupark, Vienna-Donaustadt - ca. 160 m a.s.l. Habitat: sandy area Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaves and stem** — Smooth, lance-shaped leaves along an upright toadflax stem, viewed against the sky.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Linaria_genistifolia_(subsp._genistifolia)_sl48.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/26/Linaria_genistifolia_%28subsp._genistifolia%29_sl48.jpg). Source-identified photograph with visual consistency check Stem with leaves Taxonym: Linaria genistifolia (subsp. genistifolia) ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Steinberg near Ernstbrunn, district Korneuburg, Lower Austria - ca. 450 m a.s.l. Habitat: semi-dry grassland Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Tall, slender, branching toadflax plant rising above surrounding grassland vegetation.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Linaria_genistifolia_(subsp._genistifolia)_sl35.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f6/Linaria_genistifolia_%28subsp._genistifolia%29_sl35.jpg). Source-identified photograph with visual consistency check Habitus Taxonym: Linaria genistifolia (subsp. genistifolia) ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Wolfseck km northeast of Ladendorf, district Mistelbach, Lower Austria - ca. 240 m a.s.l. Habitat: fallow land Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
The federal guide distinguishes L. genistifolia by smaller flowers and capsules; narrow leaves alone are unreliable. [F-toadflaxes](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf)
## Plants & habitat
Colorado lists this taxon separately. The 2016 federal guide considered its North American distribution unconfirmed, so a state listing is not proof of a local population. [F-toadflaxes](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
*Evidence scope: Regulatory listing and historical taxonomic uncertainty.*
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-toadflaxes** — [Biology and Biological Control of Dalmatian and Yellow Toadflax](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf), USDA Forest Service. Accessed 2026-09-07T01:19:10+00:00. Locator: Species or hybrid identity, description and ecology.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=narrow-leaved-dalmatian-toadflax) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Colorado’s listing name is retained. Drought-stressed L. dalmatica and hybrid toadflaxes can also have narrow leaves. Photographs from Europe show source-identified L. genistifolia; they do not confirm Colorado occurrence. Expert identification is needed before assigning a local plant to this taxon.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| narrow-leaved-dalmatian-toadflax-1 | Recognize | Species-specific | F-toadflaxes | No quantitative safe exposure established here. |
| narrow-leaved-dalmatian-toadflax-2 | Plants & habitat | Regulatory listing and historical taxonomic uncertainty | F-toadflaxes, CO-rules-2025 | No quantitative safe exposure established here. |
| narrow-leaved-dalmatian-toadflax-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| narrow-leaved-dalmatian-toadflax-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| narrow-leaved-dalmatian-toadflax-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/index.md
---
{
"id": "netseed-lambsquarters",
"name": "Netseed lambsquarters",
"scientific": "Chenopodium berlandieri",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A fast-growing volunteer; pet toxicity remains unresolved",
"warning_tone": "caution",
"aliases": [
"netseed goosefoot"
],
"taxonomy_note": "The Colorado flora assessment lists native Chenopodium berlandieri var. zschackii. This broader species profile does not identify every variety. It is separate from Chenopodium album; hazard claims for that species have not been transferred here.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"C-descriptions",
"S27"
],
"description": "Netseed lambsquarters: A fast-growing volunteer; pet toxicity remains unresolved. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"C-descriptions"
],
"scope": "Species description; identification limitation",
"note": "",
"id": "netseed-lambsquarters-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "netseed-lambsquarters-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "netseed-lambsquarters-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "netseed-lambsquarters-4"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "netseed-lambsquarters-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "netseed-lambsquarters-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"netseed-lambsquarters-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"netseed-lambsquarters-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"netseed-lambsquarters-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 44; Chenopodium berlandieri",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Chenopodium berlandieri"
},
"source": "content/plants/netseed-lambsquarters.md"
}
---
# Netseed lambsquarters
*Chenopodium berlandieri*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A fast-growing volunteer; pet toxicity remains unresolved.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The Colorado flora assessment lists native Chenopodium berlandieri var. zschackii. This broader species profile does not identify every variety. It is separate from Chenopodium album; hazard claims for that species have not been transferred here.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A small upright leafy goosefoot plant growing among stones in open ground.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_berlandieri_(3767481167).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7e/Chenopodium_berlandieri_%283767481167%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. berlandieri. Goosefoot species and infraspecific taxa can be difficult to distinguish, and mature seed surface characters may be needed. Foliage photographs alone do not establish an unknown plant’s species or variety; mixed Atriplex/Chenopodium comparison scenes were excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf** — Close view of a pale green, irregularly toothed leaf with a mealy-looking surface.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_berlandieri_(3767482897).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d6/Chenopodium_berlandieri_%283767482897%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. berlandieri. Goosefoot species and infraspecific taxa can be difficult to distinguish, and mature seed surface characters may be needed. Foliage photographs alone do not establish an unknown plant’s species or variety; mixed Atriplex/Chenopodium comparison scenes were excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**reproductive-clusters** — Close view of crowded green reproductive clusters beside a branching yellow-green stem.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_berlandieri_(5133107546).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/19/Chenopodium_berlandieri_%285133107546%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. berlandieri. Goosefoot species and infraspecific taxa can be difficult to distinguish, and mature seed surface characters may be needed. Foliage photographs alone do not establish an unknown plant’s species or variety; mixed Atriplex/Chenopodium comparison scenes were excluded. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An annual with variable leaves, a mealy underside and grooved stems; green flowers are inconspicuous. Confirm mature seed characters before separating it from common lambsquarters. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
*Evidence scope: Species description; identification limitation.*
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
Rapid growth and water use can make it competitive in cultivated ground. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Management & timing
Pull or hoe young plants and prevent seed maturation where they are unwanted. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=netseed-lambsquarters) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 44; Chenopodium berlandieri. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The Colorado flora assessment lists native Chenopodium berlandieri var. zschackii. This broader species profile does not identify every variety. It is separate from Chenopodium album; hazard claims for that species have not been transferred here.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| netseed-lambsquarters-1 | Identification | Species description; identification limitation | C-descriptions | No quantitative safe exposure established here. |
| netseed-lambsquarters-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| netseed-lambsquarters-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| netseed-lambsquarters-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| netseed-lambsquarters-5 | Plants & habitat | Species-specific | C-descriptions | No quantitative safe exposure established here. |
| netseed-lambsquarters-6 | Management & timing | Species-specific | C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/index.md
---
{
"id": "orange-hawkweed",
"name": "Orange hawkweed",
"scientific": "Pilosella aurantiaca",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Runners crowd lawns and mountain meadows",
"warning_tone": "caution",
"aliases": [
"Hieracium aurantiacum",
"orange paintbrush",
"devil’s paintbrush"
],
"taxonomy_note": "Colorado lists the synonym Hieracium aurantiacum. The name orange paintbrush must not be confused with native Castilleja species.",
"source_ids": [
"CO-rules-2025",
"WA-orange-hawkweed",
"S27",
"Fremont-list-definitions"
],
"description": "Orange hawkweed: Runners crowd lawns and mountain meadows. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-orange-hawkweed"
],
"scope": "Species-specific",
"note": "",
"id": "orange-hawkweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-orange-hawkweed"
],
"scope": "Species-specific",
"note": "",
"id": "orange-hawkweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "orange-hawkweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "orange-hawkweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "orange-hawkweed-5"
},
{
"id": "orange-hawkweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"orange-hawkweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"orange-hawkweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"orange-hawkweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/orange-hawkweed.md"
}
---
# Orange hawkweed
*Pilosella aurantiaca*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Runners crowd lawns and mountain meadows.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado lists the synonym Hieracium aurantiacum. The name orange paintbrush must not be confused with native Castilleja species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers** — A compact group of bright orange-red flower heads with yellow centres.
Photo: Tom Norton; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/221521260); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/392306651/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Several flowering stems rising from mixed low grassland vegetation.
Photo: Tom Norton; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/221521260); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/392306695/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem hairs** — Close view of conspicuously hairy flower stems and surrounding foliage.
Photo: Tom Norton; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/221521260); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/392306710/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Clusters of vivid orange-red flowerheads rise over hairy basal leaves; flowering stems carry few leaves. [WA-orange-hawkweed](https://www.nwcb.wa.gov/weeds/orange-hawkweed)
## Plants & habitat
Seed, surface runners and rhizomes produce spreading patches that crowd out desirable forage and meadow plants. [WA-orange-hawkweed](https://www.nwcb.wa.gov/weeds/orange-hawkweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-orange-hawkweed** — [Orange Hawkweed](https://www.nwcb.wa.gov/weeds/orange-hawkweed), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:01+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=orange-hawkweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Colorado lists the synonym Hieracium aurantiacum. The name orange paintbrush must not be confused with native Castilleja species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| orange-hawkweed-1 | Recognize | Species-specific | WA-orange-hawkweed | No quantitative safe exposure established here. |
| orange-hawkweed-2 | Plants & habitat | Species-specific | WA-orange-hawkweed | No quantitative safe exposure established here. |
| orange-hawkweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| orange-hawkweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| orange-hawkweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/index.md
---
{
"id": "oxeye-daisy",
"name": "Oxeye daisy",
"scientific": "Leucanthemum vulgare",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-oxeye-daisy"
],
"warning": "Toxic to dogs and cats; dermatitis",
"warning_tone": "danger",
"aliases": [
"Chrysanthemum leucanthemum"
],
"taxonomy_note": "ASPCA’s page titled Daisy names Chrysanthemum species, not Leucanthemum vulgare. It is excluded as direct pet evidence; the species-specific NC State account supports the warning here.",
"source_ids": [
"J-oxeye-daisy",
"N-leucanthemum-vulgare",
"Fremont-list-definitions"
],
"description": "Oxeye daisy: Toxic to dogs and cats; dermatitis. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-leucanthemum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "oxeye-daisy-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-oxeye-daisy"
],
"scope": "Species-specific",
"note": "",
"id": "oxeye-daisy-2"
},
{
"label": "People",
"sources": [
"N-leucanthemum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "oxeye-daisy-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-leucanthemum-vulgare"
],
"scope": "Species-specific",
"note": "",
"id": "oxeye-daisy-4"
},
{
"label": "Other animals",
"sources": [
"N-leucanthemum-vulgare"
],
"scope": "Source problem tag; clinical detail limited",
"note": "",
"id": "oxeye-daisy-5"
},
{
"id": "oxeye-daisy-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/oxeye-daisy.md"
}
---
# Oxeye daisy
*Leucanthemum vulgare*
**Colorado noxious weed · List B — Stop the spread.** [J-oxeye-daisy](https://www.jeffco.us/2340/Oxeye-Daisy)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Toxic to dogs and cats; dermatitis.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** ASPCA’s page titled Daisy names Chrysanthemum species, not Leucanthemum vulgare. It is excluded as direct pet evidence; the species-specific NC State account supports the warning here.
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Upright clump with many long stems carrying white-rayed yellow-centered flower heads.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:LEUCANTHEMUM_VULGARE_-_SANT_JUST_-_IB-700_(Margarida).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/a/af/LEUCANTHEMUM_VULGARE_-_SANT_JUST_-_IB-700_%28Margarida%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Oxeye daisy belongs to a taxonomically difficult group, and ornamental Shasta daisies may resemble it. Selected source photographs are labeled L. vulgare; a photograph alone does not establish cytotype or exclude every close relative. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — White ray florets surround a broad yellow disk of tiny florets in a single flower head.
Photo: Kaldari; [Public domain](https://commons.wikimedia.org/wiki/File:Leucanthemum_vulgare_Kaldari.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Leucanthemum_vulgare_Kaldari.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bd/Leucanthemum_vulgare_Kaldari.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Oxeye daisy belongs to a taxonomically difficult group, and ornamental Shasta daisies may resemble it. Selected source photographs are labeled L. vulgare; a photograph alone does not establish cytotype or exclude every close relative. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Alternate toothed to lobed stem leaves with narrow bases along slender upright stems.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Leucanthemum_vulgare_(s._str.)_sl6.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/9c/Leucanthemum_vulgare_%28s._str.%29_sl6.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Oxeye daisy belongs to a taxonomically difficult group, and ornamental Shasta daisies may resemble it. Selected source photographs are labeled L. vulgare; a photograph alone does not establish cytotype or exclude every close relative. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
White ray flowers around a yellow center, with toothed or lobed leaves; a perennial that spreads through rhizomes. [N-leucanthemum-vulgare](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/)
## Plants & habitat
Introduced ornamental that can spread in meadows and disturbed areas. Prevent seed production and manage the perennial root system. [J-oxeye-daisy](https://www.jeffco.us/2340/Oxeye-Daisy)
## People
NC State lists contact dermatitis from leaves and flowers. This guide does not assess edible use. [N-leucanthemum-vulgare](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/)
## Dogs & cats
NC State reports ingestion toxicity, with possible vomiting, diarrhea, drooling, incoordination and dermatitis. Contact a veterinarian after suspected ingestion. [N-leucanthemum-vulgare](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/)
## Other animals
The source flags horses but does not provide a horse-specific exposure assessment; no safe feed amount is established here. [N-leucanthemum-vulgare](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-oxeye-daisy** — [Oxeye Daisy](https://www.jeffco.us/2340/Oxeye-Daisy), Jefferson County, Colorado. Accessed 2026-09-07T00:27:24+00:00. Locator: Description, impacts, Colorado list designation, management.
- **N-leucanthemum-vulgare** — [Leucanthemum vulgare — Plant Toolbox](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/), NC State Extension. Accessed 2026-09-07T00:24:01+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=oxeye-daisy) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
ASPCA’s page titled Daisy names Chrysanthemum species, not Leucanthemum vulgare. It is excluded as direct pet evidence; the species-specific NC State account supports the warning here.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| oxeye-daisy-1 | Recognize | Species-specific | N-leucanthemum-vulgare | No quantitative exposure threshold established here. |
| oxeye-daisy-2 | Plants & habitat | Species-specific | J-oxeye-daisy | No quantitative exposure threshold established here. |
| oxeye-daisy-3 | People | Species-specific | N-leucanthemum-vulgare | No quantitative exposure threshold established here. |
| oxeye-daisy-4 | Dogs & cats | Species-specific | N-leucanthemum-vulgare | No quantitative exposure threshold established here. |
| oxeye-daisy-5 | Other animals | Source problem tag; clinical detail limited | N-leucanthemum-vulgare | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md
---
{
"id": "parrotfeather",
"name": "Parrotfeather",
"scientific": "Myriophyllum aquaticum",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Aquatic mats obstruct waterways",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Do not confuse this species with Eurasian watermilfoil or native Myriophyllum species.",
"source_ids": [
"CO-rules-2025",
"N-myriophyllum-aquaticum",
"S27",
"Fremont-list-definitions"
],
"description": "Parrotfeather: Aquatic mats obstruct waterways. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-myriophyllum-aquaticum"
],
"scope": "Species-specific",
"note": "",
"id": "parrotfeather-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-myriophyllum-aquaticum"
],
"scope": "Species-specific",
"note": "",
"id": "parrotfeather-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "parrotfeather-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "parrotfeather-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "parrotfeather-5"
},
{
"id": "parrotfeather-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"parrotfeather-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"parrotfeather-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"parrotfeather-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/parrotfeather.md"
}
---
# Parrotfeather
*Myriophyllum aquaticum*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Aquatic mats obstruct waterways.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Do not confuse this species with Eurasian watermilfoil or native Myriophyllum species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**emergent shoots** — Dense green, feather-leaved shoots emerging above the water surface.
Photo: Quillipede; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/327259315); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/592853044/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-whorl detail** — Close view of finely divided leaves arranged around upright stems.
Photo: Greg Tasney; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/334080916); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/606611600/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habitat** — A patch of emergent feather-leaved shoots among wet rocks.
Photo: Greg Tasney; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/334080916); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/606612099/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Feathery leaves circle the stems; leafy shoots often extend above the water surface. [N-myriophyllum-aquaticum](https://plants.ces.ncsu.edu/plants/myriophyllum-aquaticum/)
## Plants & habitat
Vegetative spread produces dense growth that competes with native aquatic plants and obstructs water use. Do not release pond or aquarium plants into waterways. [N-myriophyllum-aquaticum](https://plants.ces.ncsu.edu/plants/myriophyllum-aquaticum/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-myriophyllum-aquaticum** — [myriophyllum aquaticum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/myriophyllum-aquaticum/), NC State Extension. Accessed 2026-09-07T01:04:52+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=parrotfeather) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Do not confuse this species with Eurasian watermilfoil or native Myriophyllum species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| parrotfeather-1 | Recognize | Species-specific | N-myriophyllum-aquaticum | No quantitative safe exposure established here. |
| parrotfeather-2 | Plants & habitat | Species-specific | N-myriophyllum-aquaticum | No quantitative safe exposure established here. |
| parrotfeather-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| parrotfeather-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| parrotfeather-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md
---
{
"id": "perennial-pepperweed",
"name": "Perennial pepperweed",
"scientific": "Lepidium latifolium",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Deep roots form persistent wetland colonies",
"warning_tone": "caution",
"aliases": [
"tall whitetop"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"J-perennial-pepperweed",
"S27",
"Fremont-list-definitions"
],
"description": "Perennial pepperweed: Deep roots form persistent wetland colonies. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-perennial-pepperweed"
],
"scope": "Species-specific",
"note": "",
"id": "perennial-pepperweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-perennial-pepperweed"
],
"scope": "Species-specific",
"note": "",
"id": "perennial-pepperweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-pepperweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-pepperweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-pepperweed-5"
},
{
"id": "perennial-pepperweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"perennial-pepperweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"perennial-pepperweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"perennial-pepperweed-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/perennial-pepperweed.md"
}
---
# Perennial pepperweed
*Lepidium latifolium*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Deep roots form persistent wetland colonies.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruits** — A fruiting perennial-pepperweed branch bearing many small green oval fruits.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Lepidium_latifolium_15-p.bot-lepi.lati-17.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e3/Lepidium_latifolium_15-p.bot-lepi.lati-17.jpg). Source-identified photograph with visual consistency check Nom français : lépidie à feuilles larges. Nom anglais : broad-leaved peppergrass. Infrutescence (fruit, silicule) de lépidie à feuilles larges. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf attachment** — A broad, lightly toothed leaf attached to a pale perennial-pepperweed stem.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Lepidium_latifolium_15-p.bot-lepi.lati-27.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/13/Lepidium_latifolium_15-p.bot-lepi.lati-27.jpg). Source-identified photograph with visual consistency check Nom français : lépidie à feuilles larges. Nom anglais : broad-leaved peppergrass. Tige et feuilles caulinaires de lépidie à feuilles larges. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A patch of perennial pepperweed with broad leaves and branching clusters of small white flowers.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Lepidium_latifolium_15-p.bot-lepi.lati-19.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/22/Lepidium_latifolium_15-p.bot-lepi.lati-19.jpg). Source-identified photograph with visual consistency check Nom français : lépidie à feuilles larges. Nom anglais : broad-leaved peppergrass. Plants en fleur (inflorescence) de lépidie à feuilles larges, en milieu naturel. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Broad, waxy, alternate leaves and dense clusters of small white flowers on an upright perennial. [J-perennial-pepperweed](https://www.jeffco.us/2334/Perennial-Pepperweed)
## Plants & habitat
Invades wetlands, ditches and pastures. Deep and lateral roots produce new shoots; broken roots can spread an infestation. [J-perennial-pepperweed](https://www.jeffco.us/2334/Perennial-Pepperweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-perennial-pepperweed** — [Perennial Pepperweed](https://www.jeffco.us/2334/Perennial-Pepperweed), Jefferson County, Colorado. Accessed 2026-09-07T01:08:57+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=perennial-pepperweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| perennial-pepperweed-1 | Recognize | Species-specific | J-perennial-pepperweed | No quantitative safe exposure established here. |
| perennial-pepperweed-2 | Plants & habitat | Species-specific | J-perennial-pepperweed | No quantitative safe exposure established here. |
| perennial-pepperweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| perennial-pepperweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| perennial-pepperweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/index.md
---
{
"id": "perennial-sowthistle",
"name": "Perennial sowthistle",
"scientific": "Sonchus arvensis",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Persistent underground spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Annual sowthistles are separate species. A yellow flowerhead and milky sap are insufficient identification.",
"source_ids": [
"CO-rules-2025",
"J-perennial-sowthistle",
"S27",
"Fremont-list-definitions"
],
"description": "Perennial sowthistle: Persistent underground spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-perennial-sowthistle"
],
"scope": "Species-specific",
"note": "",
"id": "perennial-sowthistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-perennial-sowthistle"
],
"scope": "Species-specific",
"note": "",
"id": "perennial-sowthistle-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-sowthistle-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-sowthistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "perennial-sowthistle-5"
},
{
"id": "perennial-sowthistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"perennial-sowthistle-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"perennial-sowthistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"perennial-sowthistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/perennial-sowthistle.md"
}
---
# Perennial sowthistle
*Sonchus arvensis*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Persistent underground spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Annual sowthistles are separate species. A yellow flowerhead and milky sap are insufficient identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Branched upright sowthistle bearing yellow flower heads above deeply lobed foliage.
Photo: Gabriele Kothe-Heinrich; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Sonchus_arvensis_Helgoland.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b4/Sonchus_arvensis_Helgoland.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Long blue-green toothed leaf with a clasping base around an upright stem.
Photo: Anneli Salo; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Sonchus_arvensis_Peltovalvatti_C_H8939.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/42/Sonchus_arvensis_Peltovalvatti_C_H8939.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — A yellow head composed of many narrow strap-shaped florets.
Photo: Bogdan; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Sonchus_arvensis_2_bgiu.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/46/Sonchus_arvensis_2_bgiu.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow dandelion-like flowerheads on leafy stalks; leaves clasp the stem and may have prickly margins. [J-perennial-sowthistle](https://www.jeffco.us/2323/Perennial-Sowthistle)
## Plants & habitat
A perennial of moist disturbed places with spreading underground growth. Seed prevention and repeated follow-up are needed. [J-perennial-sowthistle](https://www.jeffco.us/2323/Perennial-Sowthistle)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-perennial-sowthistle** — [Perennial Sowthistle](https://www.jeffco.us/2323/Perennial-Sowthistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:24+00:00. Locator: Description, impacts, Colorado list designation, management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=perennial-sowthistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Annual sowthistles are separate species. A yellow flowerhead and milky sap are insufficient identification.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| perennial-sowthistle-1 | Recognize | Species-specific | J-perennial-sowthistle | No quantitative safe exposure established here. |
| perennial-sowthistle-2 | Plants & habitat | Species-specific | J-perennial-sowthistle | No quantitative safe exposure established here. |
| perennial-sowthistle-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| perennial-sowthistle-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| perennial-sowthistle-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md
---
{
"id": "plains-pricklypear",
"name": "Plains pricklypear",
"scientific": "Opuntia polyacantha",
"category": "xeriscape",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Sharp spines around paws, mouths and eyes",
"warning_tone": "caution",
"aliases": [
"plains prickly pear",
"prickly pear cactus"
],
"taxonomy_note": "Many Opuntia species share prickly-pear names. Source photographs are species references, not a complete key to Colorado cacti or a basis for edible-fruit identification.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-opuntia",
"C-low-water-cactus",
"S27"
],
"description": "Plains pricklypear: Sharp spines around paws, mouths and eyes. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-opuntia"
],
"scope": "Species-specific",
"note": "",
"id": "plains-pricklypear-1"
},
{
"label": "People",
"sources": [
"F-opuntia"
],
"scope": "Mechanical-injury precaution inferred from spines",
"note": "",
"id": "plains-pricklypear-2"
},
{
"label": "Dogs & cats",
"sources": [
"F-opuntia"
],
"scope": "Mechanical-injury precaution; toxicology unresolved",
"note": "",
"id": "plains-pricklypear-3"
},
{
"label": "Other animals",
"sources": [
"F-opuntia"
],
"scope": "Species-specific",
"note": "",
"id": "plains-pricklypear-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-opuntia",
"C-low-water-cactus"
],
"scope": "Species-specific",
"note": "",
"id": "plains-pricklypear-5"
},
{
"label": "Management & timing",
"sources": [
"F-opuntia"
],
"scope": "Placement and handling precaution",
"note": "",
"id": "plains-pricklypear-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"plains-pricklypear-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 66; Opuntia polyacantha",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Opuntia polyacantha"
},
"source": "content/plants/plains-pricklypear.md"
}
---
# Plains pricklypear
*Opuntia polyacantha*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Sharp spines around paws, mouths and eyes.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Many Opuntia species share prickly-pear names. Source photographs are species references, not a complete key to Colorado cacti or a basis for edible-fruit identification.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit-spines** — Low cluster of plains pricklypear pads covered with long pale spines on dry ground.
Photo: eigenmotion; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/88425296); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/146118429/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower** — Open yellow plains pricklypear flower above a spiny pad, with a dried flower beside it.
Photo: Kathlin Simpkins; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/169532573); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/293924446/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**pads** — Green plains pricklypear pads with widely spaced pale spine clusters among grasses.
Photo: dghjertaas; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/204052384); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/360613213/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A low, mat-forming cactus with flattened pads, clusters of spines and fruits that dry at maturity. Several varieties are included within this species. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol)
## People
Pads and fruits carry sharp points. Avoid bare-hand handling; eye contact deserves prompt medical assessment. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol)
*Evidence scope: Mechanical-injury precaution inferred from spines.*
## Dogs & cats
Keep animals from running into, biting or pawing the cactus. Spines create a mechanical injury risk; chemical ingestion toxicity is not established here. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol)
*Evidence scope: Mechanical-injury precaution; toxicology unresolved.*
## Other animals
Some wildlife eat it. Livestock forage use described by the Forest Service does not eliminate the hazard of intact spines. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol)
## Plants & habitat
A native of dry grasslands and shrublands and a participant in CSU’s very-low-water demonstration garden. It can be desirable away from heavy foot or pet traffic. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol) [C-low-water-cactus](https://elpaso.extension.colostate.edu/native-plant-demonstration-garden/very-low-water-garden/)
## Management & timing
Choose placement with room around walkways and animal routes. Inspect for detached pads before allowing pets back into a worked area. [F-opuntia](https://research.fs.usda.gov/feis/species-reviews/opupol)
*Evidence scope: Placement and handling precaution.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-opuntia** — [Plains pricklypear](https://research.fs.usda.gov/feis/species-reviews/opupol), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **C-low-water-cactus** — [Very Low Water Garden](https://elpaso.extension.colostate.edu/native-plant-demonstration-garden/very-low-water-garden/), Colorado State University Extension, El Paso County. Accessed 2026-09-07T02:33:43+00:00. Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=plains-pricklypear) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 66; Opuntia polyacantha. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Many Opuntia species share prickly-pear names. Source photographs are species references, not a complete key to Colorado cacti or a basis for edible-fruit identification.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| plains-pricklypear-1 | Identification | Species-specific | F-opuntia | No quantitative safe exposure established here. |
| plains-pricklypear-2 | People | Mechanical-injury precaution inferred from spines | F-opuntia | No quantitative safe exposure established here. |
| plains-pricklypear-3 | Dogs & cats | Mechanical-injury precaution; toxicology unresolved | F-opuntia | No quantitative safe exposure established here. |
| plains-pricklypear-4 | Other animals | Species-specific | F-opuntia | No quantitative safe exposure established here. |
| plains-pricklypear-5 | Plants & habitat | Species-specific | F-opuntia, C-low-water-cactus | No quantitative safe exposure established here. |
| plains-pricklypear-6 | Management & timing | Placement and handling precaution | F-opuntia | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/index.md
---
{
"id": "plumeless-thistle",
"name": "Plumeless thistle",
"scientific": "Carduus acanthoides",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Sharp spines; pasture competition",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Distinguish introduced Carduus from Colorado’s native thistles before removal.",
"source_ids": [
"CO-rules-2025",
"J-plumeless-thistle",
"S27",
"Fremont-list-definitions"
],
"description": "Plumeless thistle: Sharp spines; pasture competition. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-plumeless-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "plumeless-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-plumeless-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "plumeless-thistle-2"
},
{
"label": "People",
"sources": [
"J-plumeless-thistle"
],
"scope": "Physical-risk inference",
"note": "",
"id": "plumeless-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-plumeless-thistle"
],
"scope": "Physical-risk inference; ingestion evidence gap",
"note": "",
"id": "plumeless-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "plumeless-thistle-5"
},
{
"id": "plumeless-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"plumeless-thistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"plumeless-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/plumeless-thistle.md"
}
---
# Plumeless thistle
*Carduus acanthoides*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; pasture competition.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinguish introduced Carduus from Colorado’s native thistles before removal.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf** — Flatbed photographic scan of a deeply lobed, spiny plumeless-thistle leaf with a millimeter scale.
Photo: Dmitry Makeev; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:2020_year._Herbarium._Carduus_acanthoides._img-009.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/74/2020_year._Herbarium._Carduus_acanthoides._img-009.jpg). Source-identified photograph with visual consistency check Carduus acanthoides. Leaf adaxial side. Herbarium of the city Elektrostal Moscow Oblast, 2020 year. Created by scanography. Collection D.Makeev. Scale 1 unit = 1 mm. These are original colors. Please do not make edit. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering stem** — Pink-purple plumeless-thistle flower heads above an extensively winged, spiny stem.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carduus_acanthoides_2_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4d/Carduus_acanthoides_2_RF.jpg). Source-identified photograph with visual consistency check Spiny plumeless thistle ( Carduus acanthoides ), near Groß-Gerau-Wallerstädten at the bike path along L3094, Germany Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers and seed dispersal** — Purple plumeless-thistle heads beside a mature head releasing pale feathery seed structures.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carduus_acanthoides_4_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/26/Carduus_acanthoides_4_RF.jpg). Source-identified photograph with visual consistency check Spiny plumeless thistle ( Carduus acanthoides ) at the bike path between Egelsbach and Erzhausen , Germany Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A spiny thistle with winged stems and relatively small, reddish-purple flowerheads. [J-plumeless-thistle](https://www.jeffco.us/2294/Plumeless-Thistle)
## Plants & habitat
Spreads by seed through disturbed pasture and roadsides. Follow-up is needed as rosettes germinate. [J-plumeless-thistle](https://www.jeffco.us/2294/Plumeless-Thistle)
## People
Spines on leaves, stems and flowerhead bracts can puncture skin; use protective handling. [J-plumeless-thistle](https://www.jeffco.us/2294/Plumeless-Thistle)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Spines may injure mouths or paws. Pet-specific chemical toxicity is not established here. [J-plumeless-thistle](https://www.jeffco.us/2294/Plumeless-Thistle)
*Evidence scope: Physical-risk inference; ingestion evidence gap.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-plumeless-thistle** — [Plumeless Thistle](https://www.jeffco.us/2294/Plumeless-Thistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:24+00:00. Locator: Description, impacts, Colorado list designation, management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=plumeless-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Distinguish introduced Carduus from Colorado’s native thistles before removal.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| plumeless-thistle-1 | Recognize | Species-specific | J-plumeless-thistle | No quantitative safe exposure established here. |
| plumeless-thistle-2 | Plants & habitat | Species-specific | J-plumeless-thistle | No quantitative safe exposure established here. |
| plumeless-thistle-3 | People | Physical-risk inference | J-plumeless-thistle | No quantitative safe exposure established here. |
| plumeless-thistle-4 | Dogs & cats | Physical-risk inference; ingestion evidence gap | J-plumeless-thistle | No quantitative safe exposure established here. |
| plumeless-thistle-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md
---
{
"id": "poison-hemlock",
"name": "Poison hemlock",
"scientific": "Conium maculatum",
"category": "invasive",
"status": "Colorado List C — Manage widespread weeds",
"status_sources": [
"S16"
],
"warning": "Poisonous to people & animals",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S16",
"S26",
"S04",
"Fremont-list-definitions"
],
"description": "Poison hemlock: Poisonous to people & animals. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S16"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "poison-hemlock-1"
},
{
"label": "Plants & habitat",
"sources": [
"S16"
],
"scope": "Species-specific + garden judgment",
"note": "Access restriction and referral are cautious editorial advice based on documented poisoning.",
"reviewed": "2026-09-06",
"id": "poison-hemlock-2"
},
{
"label": "People",
"sources": [
"S16",
"S26"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "poison-hemlock-3"
},
{
"label": "Dogs & cats",
"sources": [
"S16",
"S04"
],
"scope": "Broad animal warning; pet precaution",
"note": "Pet recommendation applies general animal toxicity plus ASPCA's prompt-contact guidance; it is not a species-specific dose estimate.",
"reviewed": "2026-09-06",
"id": "poison-hemlock-4"
},
{
"label": "Other animals",
"sources": [
"S16"
],
"scope": "Species-specific + interpretation",
"note": "Risk interpretation follows the county page listing both List C and toxicity.",
"reviewed": "2026-09-06",
"id": "poison-hemlock-5"
},
{
"id": "poison-hemlock-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/poison-hemlock.md"
}
---
# Poison hemlock
*Conium maculatum*
**Colorado List C — Manage widespread weeds.** [S16](https://www.jeffco.us/2230/Poison-Hemlock)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Poisonous to people & animals.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Tall branching plant with many small white compound umbels above finely divided foliage.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Conium_maculatum_kz01_2021-06-23_R%C3%B3wne.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/65/Conium_maculatum_kz01_2021-06-23_R%C3%B3wne.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem** — Smooth green stem with conspicuous purple-red blotches beside finely divided leaves.
Photo: MPF; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Conium_maculatum_Hauxley_2.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f7/Conium_maculatum_Hauxley_2.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Small white flowers in compound umbels, with finely divided leaves visible beside them.
Photo: Nicolas Ramirez; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Conium_maculatum_007.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/03/Conium_maculatum_007.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Finely divided leaves, stems with purple spots, and white umbrella-like flower clusters. Often near streams, ditches, and pasture edges. [S16](https://www.jeffco.us/2230/Poison-Hemlock)
## Plants & habitat
An introduced, colony-forming biennial. Garden judgment: exclude access and seek local management help once identification is confirmed. [S16](https://www.jeffco.us/2230/Poison-Hemlock)
## People
All parts are poisonous. Do not eat or taste it to identify it. Suspected ingestion warrants immediate Poison Control advice. [S16](https://www.jeffco.us/2230/Poison-Hemlock) [S26](https://www.poison.org/first-aid-for-poisonings)
## Dogs & cats
The county warning covers animals broadly. Treat suspected ingestion by a pet as urgent and contact a veterinarian. [S16](https://www.jeffco.us/2230/Poison-Hemlock) [S04](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed)
## Other animals
Poisonous to livestock; do not use grazing as a control method. A List C designation does not indicate low toxicity. [S16](https://www.jeffco.us/2230/Poison-Hemlock)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S16** — [Poison Hemlock](https://www.jeffco.us/2230/Poison-Hemlock), Jefferson County, Colorado. Accessed 2026-09-07T00:23:54+00:00. Locator: List C designation; General; Habitat; Vegetation; Flower.
- **S26** — [First aid guidelines](https://www.poison.org/first-aid-for-poisonings), National Capital Poison Center. Accessed 2026-09-07T00:23:56+00:00. Locator: Poison center phone; emergency symptoms; do not induce vomiting.
- **S04** — [Milkweed](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed), ASPCA Poison Control. Accessed 2026-09-07T00:23:52+00:00. Locator: Scientific Name; Toxicity; Clinical Signs; poison contact.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=poison-hemlock) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| poison-hemlock-1 | Recognize | Species-specific | S16 | No quantitative exposure threshold established here. |
| poison-hemlock-2 | Plants & habitat | Species-specific + garden judgment | S16 | Access restriction and referral are cautious editorial advice based on documented poisoning. |
| poison-hemlock-3 | People | Species-specific | S16, S26 | No quantitative exposure threshold established here. |
| poison-hemlock-4 | Dogs & cats | Broad animal warning; pet precaution | S16, S04 | Pet recommendation applies general animal toxicity plus ASPCA's prompt-contact guidance; it is not a species-specific dose estimate. |
| poison-hemlock-5 | Other animals | Species-specific + interpretation | S16 | Risk interpretation follows the county page listing both List C and toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/index.md
---
{
"id": "prairie-sage",
"name": "Prairie sage",
"scientific": "Artemisia ludoviciana",
"category": "native",
"status": "Colorado native",
"status_sources": [
"S03"
],
"warning": "Spreading roots; pet evidence gap",
"warning_tone": "caution",
"aliases": [
"white sage",
"white sagebrush"
],
"taxonomy_note": "Common name white sage also refers to other plants, including Salvia apiana. Do not merge their uses or toxicology.",
"source_ids": [
"S03",
"N-artemisia-ludoviciana"
],
"description": "Prairie sage: Spreading roots; pet evidence gap. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-artemisia-ludoviciana"
],
"scope": "Species-specific",
"note": "",
"id": "prairie-sage-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-artemisia-ludoviciana"
],
"scope": "Species-specific",
"note": "",
"id": "prairie-sage-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed gardening source does not establish human ingestion safety.",
"id": "prairie-sage-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "prairie-sage-4"
},
{
"label": "Other animals",
"sources": [
"S03"
],
"scope": "Species-specific wildlife use; toxicity gap",
"note": "",
"id": "prairie-sage-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"prairie-sage-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"prairie-sage-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"prairie-sage-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/prairie-sage.md"
}
---
# Prairie sage
*Artemisia ludoviciana*
**Colorado native.** [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf)
> **Spreading roots; pet evidence gap.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Common name white sage also refers to other plants, including Salvia apiana. Do not merge their uses or toxicology.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**leaves** — Dense, silvery foliage with narrow leaves, some divided into slender lobes.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_ludoviciana_(4022881472).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/92/Artemisia_ludoviciana_%284022881472%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and habitat** — A broad patch of upright silvery stems and narrow flowering stalks in a rocky woodland opening.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_ludoviciana_ssp._incompta_(8001060861).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8f/Artemisia_ludoviciana_ssp._incompta_%288001060861%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering habit** — A clump on a rocky slope, showing leafy stems topped by narrow branched flower stalks.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Artemisia_ludoviciana_ssp._incompta_-_white_sagebrush_-_Flickr_-_Matt_Lavin_(1).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/82/Artemisia_ludoviciana_ssp._incompta_-_white_sagebrush_-_Flickr_-_Matt_Lavin_%281%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An upright silver-leaved perennial with small, inconspicuous flowerheads. [N-artemisia-ludoviciana](https://plants.ces.ncsu.edu/plants/artemisia-ludoviciana/)
## Plants & habitat
Spreads by rhizomes and seed, sometimes becoming weedy. Dry, well-drained soil suits it; leave room or manage expansion at bed edges. [N-artemisia-ludoviciana](https://plants.ces.ncsu.edu/plants/artemisia-ludoviciana/)
## People
The reviewed gardening source does not establish human ingestion safety. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
The Front Range guide records pollen and seed value for insects and birds. Those benefits do not establish livestock or pet safety. [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S03** — [Low-Water Native Plants for Colorado Gardens: Front Range & Foothills](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf), Colorado Native Plant Society / CSU Extension. Accessed 2026-09-07T00:23:53+00:00. Locator: Plant table: Asclepias speciosa and Achillea millefolium.
- **N-artemisia-ludoviciana** — [Artemisia ludoviciana — Plant Toolbox](https://plants.ces.ncsu.edu/plants/artemisia-ludoviciana/), NC State Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=prairie-sage) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Common name white sage also refers to other plants, including Salvia apiana. Do not merge their uses or toxicology.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| prairie-sage-1 | Recognize | Species-specific | N-artemisia-ludoviciana | No quantitative exposure threshold established here. |
| prairie-sage-2 | Plants & habitat | Species-specific | N-artemisia-ludoviciana | No quantitative exposure threshold established here. |
| prairie-sage-3 | People | Review limitation | Review limitation | The reviewed gardening source does not establish human ingestion safety. |
| prairie-sage-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| prairie-sage-5 | Other animals | Species-specific wildlife use; toxicity gap | S03 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/index.md
---
{
"id": "prickly-lettuce",
"name": "Prickly lettuce",
"scientific": "Lactuca serriola",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Prickly leaves and prolific windborne seed",
"warning_tone": "caution",
"aliases": [
"compassplant",
"wild lettuce"
],
"taxonomy_note": "Wild lettuce names refer to several species. Lactuca serriola is not a substitute for cultivated lettuce or a verified medicinal product.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"C-descriptions",
"S27"
],
"description": "Prickly lettuce: Prickly leaves and prolific windborne seed. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-lettuce-1"
},
{
"label": "People",
"sources": [
"C-descriptions"
],
"scope": "Handling precaution inferred from leaf structure",
"note": "",
"id": "prickly-lettuce-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prickly-lettuce-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prickly-lettuce-4"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-lettuce-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-lettuce-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"prickly-lettuce-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"prickly-lettuce-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 60; Lactuca serriola",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Lactuca serriola"
},
"source": "content/plants/prickly-lettuce.md"
}
---
# Prickly lettuce
*Lactuca serriola*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Prickly leaves and prolific windborne seed.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Wild lettuce names refer to several species. Lactuca serriola is not a substitute for cultivated lettuce or a verified medicinal product.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — A pale yellow flower head composed of narrow strap-shaped florets.
Photo: Teun Spaans (TeunSpaans); [Public domain](https://commons.wikimedia.org/wiki/File:Kompassla_08-07-2006_9.38.20.JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Kompassla_08-07-2006_9.38.20.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/9/91/Kompassla_08-07-2006_9.38.20.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified L. serriola. Leaf lobing varies, and related wild lettuces may share a prickly midrib; the photograph is a reference, not a determination of an unknown specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — Tall branching prickly lettuce stems rise above surrounding vegetation.
Photo: Teun Spaans (TeunSpaans); [Public domain](https://commons.wikimedia.org/wiki/File:Kompassla_06-07-2006_13.12.04.JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Kompassla_06-07-2006_13.12.04.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4f/Kompassla_06-07-2006_13.12.04.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified L. serriola. Leaf lobing varies, and related wild lettuces may share a prickly midrib; the photograph is a reference, not a determination of an unknown specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-midrib** — Underside of a long green leaf with a prominent pale midrib lined with stiff prickles.
Photo: Teun Spaans (TeunSpaans); [Public domain](https://commons.wikimedia.org/wiki/File:Kompassla_08-07-2006_9.39.08.JPG#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Kompassla_08-07-2006_9.39.08.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/9/91/Kompassla_08-07-2006_9.39.08.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified L. serriola. Leaf lobing varies, and related wild lettuces may share a prickly midrib; the photograph is a reference, not a determination of an unknown specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An upright annual or biennial with milky sap, spines along the underside of the leaf midrib and small yellow flower heads. Leaves may stand nearly vertical. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## People
Leaf spines are a handling concern. No ingestion safety is established by this profile. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
*Evidence scope: Handling precaution inferred from leaf structure.*
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It invades disturbed garden soils. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Management & timing
Pull young plants from moist soil before flowers mature. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=prickly-lettuce) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 60; Lactuca serriola. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Wild lettuce names refer to several species. Lactuca serriola is not a substitute for cultivated lettuce or a verified medicinal product.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| prickly-lettuce-1 | Identification | Species-specific | C-descriptions | No quantitative safe exposure established here. |
| prickly-lettuce-2 | People | Handling precaution inferred from leaf structure | C-descriptions | No quantitative safe exposure established here. |
| prickly-lettuce-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prickly-lettuce-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prickly-lettuce-5 | Plants & habitat | Species-specific | C-descriptions | No quantitative safe exposure established here. |
| prickly-lettuce-6 | Management & timing | Species-specific | C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/index.md
---
{
"id": "prickly-sowthistle",
"name": "Prickly sowthistle",
"scientific": "Sonchus asper",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Spiny leaves and rapid seed production",
"warning_tone": "caution",
"aliases": [
"spiny sowthistle"
],
"taxonomy_note": "This is an annual Sonchus, not a true Cirsium thistle and not perennial sowthistle. Confirm leaf bases and life cycle.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-sonchus-asper",
"U-sowthistle",
"S27"
],
"description": "Prickly sowthistle: Spiny leaves and rapid seed production. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-sonchus-asper",
"U-sowthistle"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-sowthistle-1"
},
{
"label": "People",
"sources": [
"N-sonchus-asper"
],
"scope": "Handling precaution inferred from leaf structure",
"note": "",
"id": "prickly-sowthistle-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prickly-sowthistle-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prickly-sowthistle-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-sonchus-asper"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-sowthistle-5"
},
{
"label": "Management & timing",
"sources": [
"N-sonchus-asper"
],
"scope": "Species-specific",
"note": "",
"id": "prickly-sowthistle-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"prickly-sowthistle-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"prickly-sowthistle-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 80; Sonchus asper",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Sonchus asper"
},
"source": "content/plants/prickly-sowthistle.md"
}
---
# Prickly sowthistle
*Sonchus asper*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Spiny leaves and rapid seed production.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is an annual Sonchus, not a true Cirsium thistle and not perennial sowthistle. Confirm leaf bases and life cycle.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A tall flowering prickly sow-thistle with lobed leaves beside a tree trunk.
Photo: Didier Descouens; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:(MHNT)_Sonchus_asper_-_Plant_habit.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/73/%28MHNT%29_Sonchus_asper_-_Plant_habit.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source identification is retained. The rounded clasping leaf lobes and prickly leaf edges are shown for comparison with S. oleraceus; hybrids and other lookalikes require a full key. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf attachment** — Glossy, spine-toothed leaves clasping the stem with rounded basal lobes.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/138412061); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/236567927/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source identification is retained. The rounded clasping leaf lobes and prickly leaf edges are shown for comparison with S. oleraceus; hybrids and other lookalikes require a full key. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**seed head** — A rounded white pappus head ready to release its fruits.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Sonchus_asper_(4971087345).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/49/Sonchus_asper_%284971087345%29.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Source identification is retained. The rounded clasping leaf lobes and prickly leaf edges are shown for comparison with S. oleraceus; hybrids and other lookalikes require a full key. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An annual with yellow flower heads and often glossy, prickly-edged leaves. Rounded basal leaf lobes clasp the stem, unlike the more pointed lobes of annual sowthistle. [N-sonchus-asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/) [U-sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/)
## People
Spiny leaf edges warrant care when handling. No ingestion safety has been established here. [N-sonchus-asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/)
*Evidence scope: Handling precaution inferred from leaf structure.*
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It grows in gardens, roadsides and disturbed ground. Plants can bolt quickly, and seeds travel by wind and water. [N-sonchus-asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/)
## Management & timing
Inspect patches often and remove unwanted plants before fluffy seedheads form. [N-sonchus-asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-sonchus-asper** — [Sonchus asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **U-sowthistle** — [Annual sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/), University of California Statewide Integrated Pest Management. Accessed 2026-09-07T02:26:10+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=prickly-sowthistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 80; Sonchus asper. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is an annual Sonchus, not a true Cirsium thistle and not perennial sowthistle. Confirm leaf bases and life cycle.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| prickly-sowthistle-1 | Identification | Species-specific | N-sonchus-asper, U-sowthistle | No quantitative safe exposure established here. |
| prickly-sowthistle-2 | People | Handling precaution inferred from leaf structure | N-sonchus-asper | No quantitative safe exposure established here. |
| prickly-sowthistle-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prickly-sowthistle-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prickly-sowthistle-5 | Plants & habitat | Species-specific | N-sonchus-asper | No quantitative safe exposure established here. |
| prickly-sowthistle-6 | Management & timing | Species-specific | N-sonchus-asper | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/index.md
---
{
"id": "prostrate-knotweed",
"name": "Prostrate knotweed",
"scientific": "Polygonum aviculare",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A mat-forming weed of compacted ground",
"warning_tone": "caution",
"aliases": [
"knotgrass",
"wiregrass"
],
"taxonomy_note": "This small lawn weed is not Japanese knotweed or another large invasive Reynoutria species. Polygonum aviculare is treated broadly here. The flower photo is source-labeled Polygonum aviculare subsp. depressum (s. lat.). Segregate-taxon boundaries remain under research; no subspecies determination is made for Colorado specimens.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-polygonum-aviculare",
"C-descriptions",
"S27"
],
"description": "Prostrate knotweed: A mat-forming weed of compacted ground. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-polygonum-aviculare"
],
"scope": "Species-specific",
"note": "",
"id": "prostrate-knotweed-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prostrate-knotweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prostrate-knotweed-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "prostrate-knotweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-polygonum-aviculare"
],
"scope": "Species-specific",
"note": "",
"id": "prostrate-knotweed-5"
},
{
"label": "Management & timing",
"sources": [
"N-polygonum-aviculare",
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "prostrate-knotweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"prostrate-knotweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"prostrate-knotweed-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"prostrate-knotweed-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 73; Polygonum aviculare",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Polygonum aviculare"
},
"source": "content/plants/prostrate-knotweed.md"
}
---
# Prostrate knotweed
*Polygonum aviculare*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A mat-forming weed of compacted ground.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This small lawn weed is not Japanese knotweed or another large invasive Reynoutria species. Polygonum aviculare is treated broadly here. The flower photo is source-labeled Polygonum aviculare subsp. depressum (s. lat.). Segregate-taxon boundaries remain under research; no subspecies determination is made for Colorado specimens.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A flattened mat of branching stems and small leaves spreads across bare soil.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Polygonum_aviculare,_Gewoon_varkensgras_plant.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/20/Polygonum_aviculare%2C_Gewoon_varkensgras_plant.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Polygonum aviculare is used as a variable species aggregate. The selected flower macro is explicitly source-labeled P. aviculare subsp. depressum (s. lat.); it is retained with that source wording. These photographs do not resolve every segregate taxon or the subspecies of an unknown Colorado specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-stem** — Narrow alternate leaves and pale papery sheaths encircle the joints of a slender stem.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Polygonum_aviculare_(5143717459).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/cd/Polygonum_aviculare_%285143717459%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Polygonum aviculare is used as a variable species aggregate. The selected flower macro is explicitly source-labeled P. aviculare subsp. depressum (s. lat.); it is retained with that source wording. These photographs do not resolve every segregate taxon or the subspecies of an unknown Colorado specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower** — Tiny pale five-parted flowers and young leaves cluster at the stem joints, photographed with a 5 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Polygonum_aviculare_subsp._depressum_(s._lat.)_sl8.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/28/Polygonum_aviculare_subsp._depressum_%28s._lat.%29_sl8.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Polygonum aviculare is used as a variable species aggregate. The selected flower macro is explicitly source-labeled P. aviculare subsp. depressum (s. lat.); it is retained with that source wording. These photographs do not resolve every segregate taxon or the subspecies of an unknown Colorado specimen. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
Look for wiry, low stems, alternating small leaves and papery sheaths around the swollen joints. Tiny flowers appear where the leaves meet the stems. [N-polygonum-aviculare](https://plants.ces.ncsu.edu/plants/polygonum-aviculare/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It tolerates trampling, poor soil and pavement cracks. A persistent seed supply helps it return where desirable vegetation struggles. [N-polygonum-aviculare](https://plants.ces.ncsu.edu/plants/polygonum-aviculare/)
## Management & timing
Mowing misses much of this low plant. Address compaction in affected turf and remove small plants before seed production. [N-polygonum-aviculare](https://plants.ces.ncsu.edu/plants/polygonum-aviculare/) [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-polygonum-aviculare** — [Polygonum aviculare](https://plants.ces.ncsu.edu/plants/polygonum-aviculare/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=prostrate-knotweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 73; Polygonum aviculare. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This small lawn weed is not Japanese knotweed or another large invasive Reynoutria species. Polygonum aviculare is treated broadly here. The flower photo is source-labeled Polygonum aviculare subsp. depressum (s. lat.). Segregate-taxon boundaries remain under research; no subspecies determination is made for Colorado specimens.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| prostrate-knotweed-1 | Identification | Species-specific | N-polygonum-aviculare | No quantitative safe exposure established here. |
| prostrate-knotweed-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prostrate-knotweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prostrate-knotweed-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| prostrate-knotweed-5 | Plants & habitat | Species-specific | N-polygonum-aviculare | No quantitative safe exposure established here. |
| prostrate-knotweed-6 | Management & timing | Species-specific | N-polygonum-aviculare, C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md
---
{
"id": "puncturevine",
"name": "Puncturevine / goathead",
"scientific": "Tribulus terrestris",
"category": "invasive",
"status": "Colorado List C — Manage widespread weeds",
"status_sources": [
"S29"
],
"warning": "Sharp burs · Animal injury",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S29",
"S17",
"S18",
"S19",
"Fremont-list-definitions"
],
"description": "Puncturevine / goathead: Sharp burs · Animal injury. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S17"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "puncturevine-1"
},
{
"label": "Plants & habitat",
"sources": [
"S18"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "puncturevine-2"
},
{
"label": "People",
"sources": [
"S17",
"S18"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "puncturevine-3"
},
{
"label": "Dogs & cats",
"sources": [
"S18",
"S19"
],
"scope": "Species-specific injury; pet precaution",
"note": "Paw-checking and play-area advice are editorial inferences from the documented spines.",
"reviewed": "2026-09-06",
"id": "puncturevine-4"
},
{
"label": "Other animals",
"sources": [
"S18"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "puncturevine-5"
},
{
"id": "puncturevine-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"puncturevine-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/puncturevine.md"
}
---
# Puncturevine / goathead
*Tribulus terrestris*
**Colorado List C — Manage widespread weeds.** [S29](https://www.larimer.gov/sites/default/files/uploads/2023/weed_management_reference_guide_-_5.5_x_8_-_jan_24_2023_-_website_reader_spreads_0.pdf)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp burs · Animal injury.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower-leaf** — Five-petaled pale yellow flower beside hairy leaves with paired oval leaflets.
Photo: Forest & Kim Starr; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Starr_030612-0063_Tribulus_terrestris.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d9/Starr_030612-0063_Tribulus_terrestris.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Prostrate branching stems and paired compound leaves spread over bare sandy soil.
Photo: Bill.pix; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Tribulus_terrestris_-_Dghoumes_National_Park.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2d/Tribulus_terrestris_-_Dghoumes_National_Park.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit** — Separate hard bur segments with stout projecting spines, photographed against a plain background with scale.
Photo: Steve Hurst @ USDA-NRCS PLANTS Database; [Public domain](https://commons.wikimedia.org/wiki/File:Trte_003_lhp.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Trte_003_lhp.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fe/Trte_003_lhp.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. None; original downloaded without modification. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Low, radiating stems with small leaflets, yellow flowers, and hard, spiny burs. Common on disturbed ground. [S17](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2109-puncture-vine/)
## Plants & habitat
Can form spreading mats and compete with other plants. Preventing seed production is central to management. [S18](https://ipm.ucanr.edu/home-and-landscape/puncturevine/)
## People
Spiny burs puncture skin and can remain a hazard after the plant dies. Use protective gloves when handling. [S17](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2109-puncture-vine/) [S18](https://ipm.ucanr.edu/home-and-landscape/puncturevine/)
## Dogs & cats
Burs can injure animals. Pet precaution: keep play areas clear of burs and check paws after contact. [S18](https://ipm.ucanr.edu/home-and-landscape/puncturevine/) [S19](https://pueblo.extension.colostate.edu/here-they-come/)
## Other animals
Burs can injure grazing animals’ mouths. Puncturevine can also be toxic to sheep; livestock findings do not establish a pet toxicity dose. [S18](https://ipm.ucanr.edu/home-and-landscape/puncturevine/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S29** — [Weed Management Reference Guide](https://www.larimer.gov/sites/default/files/uploads/2023/weed_management_reference_guide_-_5.5_x_8_-_jan_24_2023_-_website_reader_spreads_0.pdf), Larimer County, Colorado. Accessed 2026-09-07T00:24:00+00:00. Locator: Puncturevine entry: List C.
- **S17** — [2109 – Puncture Vine](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2109-puncture-vine/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:56+00:00. Locator: What is a puncture vine?; How can I control puncture vines?.
- **S18** — [Puncturevine / Home and Landscape](https://ipm.ucanr.edu/home-and-landscape/puncturevine/), University of California Statewide IPM. Accessed 2026-09-07T00:23:55+00:00. Locator: Pest Notes introduction; Identification and Life Cycle; Impact; Management.
- **S19** — [Here They Come!](https://pueblo.extension.colostate.edu/here-they-come/), CSU Extension · Pueblo County. Accessed 2026-09-07T00:23:54+00:00. Locator: Puncturevine seed-casings and animal injury; herbicide label guidance.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=puncturevine) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| puncturevine-1 | Recognize | Species-specific | S17 | No quantitative exposure threshold established here. |
| puncturevine-2 | Plants & habitat | Species-specific | S18 | No quantitative exposure threshold established here. |
| puncturevine-3 | People | Species-specific | S17, S18 | No quantitative exposure threshold established here. |
| puncturevine-4 | Dogs & cats | Species-specific injury; pet precaution | S18, S19 | Paw-checking and play-area advice are editorial inferences from the documented spines. |
| puncturevine-5 | Other animals | Species-specific | S18 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md
---
{
"id": "purple-loosestrife",
"name": "Purple loosestrife",
"scientific": "Lythrum salicaria",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Crowds out wetland vegetation",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-lythrum-salicaria",
"S27",
"Fremont-list-definitions"
],
"description": "Purple loosestrife: Crowds out wetland vegetation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-lythrum-salicaria"
],
"scope": "Species-specific",
"note": "",
"id": "purple-loosestrife-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-lythrum-salicaria"
],
"scope": "Species-specific",
"note": "",
"id": "purple-loosestrife-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "purple-loosestrife-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "purple-loosestrife-4"
},
{
"label": "Other animals",
"sources": [
"N-lythrum-salicaria"
],
"scope": "Species-specific",
"note": "",
"id": "purple-loosestrife-5"
},
{
"id": "purple-loosestrife-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"purple-loosestrife-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"purple-loosestrife-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/purple-loosestrife.md"
}
---
# Purple loosestrife
*Lythrum salicaria*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Crowds out wetland vegetation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower detail** — Close view of a purple flower with narrow petals and projecting stamens.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/281222505); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/505029214/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem and buds** — An upright bud-bearing shoot with opposite leaves and leafy bracts, photographed against a dark background.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/281222505); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/505161714/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering stand** — A dense patch of tall purple flowering spikes.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/281222505); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/505162101/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Upright spikes of purple-pink flowers above lance-shaped, opposite or whorled leaves. Stems are angular. [N-lythrum-salicaria](https://plants.ces.ncsu.edu/plants/lythrum-salicaria/)
## Plants & habitat
Extensive roots and abundant seeds enable wetland invasion. Cultivar labels do not reliably establish an inability to spread. [N-lythrum-salicaria](https://plants.ces.ncsu.edu/plants/lythrum-salicaria/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Replacement of native wetland plants reduces vegetation important to waterfowl. This ecological harm is separate from direct animal poisoning. [N-lythrum-salicaria](https://plants.ces.ncsu.edu/plants/lythrum-salicaria/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-lythrum-salicaria** — [lythrum salicaria — Plant Toolbox](https://plants.ces.ncsu.edu/plants/lythrum-salicaria/), NC State Extension. Accessed 2026-09-07T01:04:52+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=purple-loosestrife) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| purple-loosestrife-1 | Recognize | Species-specific | N-lythrum-salicaria | No quantitative safe exposure established here. |
| purple-loosestrife-2 | Plants & habitat | Species-specific | N-lythrum-salicaria | No quantitative safe exposure established here. |
| purple-loosestrife-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| purple-loosestrife-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| purple-loosestrife-5 | Other animals | Species-specific | N-lythrum-salicaria | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md
---
{
"id": "quackgrass",
"name": "Quackgrass",
"scientific": "Elymus repens",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Rhizome fragments regrow in lawns and gardens",
"warning_tone": "caution",
"aliases": [
"Elytrigia repens",
"Agropyron repens",
"couch grass"
],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"M-quackgrass",
"S27",
"Fremont-list-definitions"
],
"description": "Quackgrass: Rhizome fragments regrow in lawns and gardens. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"M-quackgrass"
],
"scope": "Species-specific",
"note": "",
"id": "quackgrass-1"
},
{
"label": "Plants & habitat",
"sources": [
"M-quackgrass"
],
"scope": "Species-specific",
"note": "",
"id": "quackgrass-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "quackgrass-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "quackgrass-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "quackgrass-5"
},
{
"id": "quackgrass-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"quackgrass-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"quackgrass-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"quackgrass-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/quackgrass.md"
}
---
# Quackgrass
*Elymus repens*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Rhizome fragments regrow in lawns and gardens.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Dense upright grass clump with long green blades and slender flower spikes.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Kweek_Elytrigia_repens.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f3/Kweek_Elytrigia_repens.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Elytrigia repens and Elymus repens are treated as synonyms. Similar grasses require spikelet orientation and leaf-collar characters for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Flattened spikelets arranged along a narrow spike, with pale anthers protruding.
Photo: James K. Lindsey; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Elymus.repens.3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c8/Elymus.repens.3.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Elytrigia repens and Elymus repens are treated as synonyms. Similar grasses require spikelet orientation and leaf-collar characters for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-node** — Close view of a leaf base and collar clasping a green culm, with a scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Elymus_repens_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e7/Elymus_repens_sl1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Elytrigia repens and Elymus repens are treated as synonyms. Similar grasses require spikelet orientation and leaf-collar characters for an unknown specimen. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A perennial grass with clasping auricles at the leaf collar and pale underground rhizomes with sharp tips. [M-quackgrass](https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/quackgrass)
## Plants & habitat
Rhizomes compete with desired vegetation and regrow from pieces. Repeated disturbance without removing or exhausting them can spread the patch. [M-quackgrass](https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/quackgrass)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **M-quackgrass** — [Quackgrass](https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/quackgrass), University of Minnesota Extension. Accessed 2026-09-07T01:16:17+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=quackgrass) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| quackgrass-1 | Recognize | Species-specific | M-quackgrass | No quantitative safe exposure established here. |
| quackgrass-2 | Plants & habitat | Species-specific | M-quackgrass | No quantitative safe exposure established here. |
| quackgrass-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| quackgrass-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| quackgrass-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/index.md
---
{
"id": "red-valerian",
"name": "Red valerian",
"scientific": "Centranthus ruber",
"category": "xeriscape",
"status": "Introduced drought-tolerant ornamental",
"status_sources": [
"N-centranthus-ruber"
],
"warning": "Self-seeds beyond garden beds",
"warning_tone": "caution",
"aliases": [
"Jupiter's beard",
"Valeriana rubra"
],
"taxonomy_note": "The retrieved NC State source now treats Centranthus ruber as Valeriana rubra. The familiar garden name is retained for discovery; it is not Valeriana officinalis.",
"source_ids": [
"N-centranthus-ruber"
],
"description": "Red valerian: Self-seeds beyond garden beds. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-centranthus-ruber"
],
"scope": "Species-specific",
"note": "",
"id": "red-valerian-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-centranthus-ruber"
],
"scope": "Species-specific",
"note": "",
"id": "red-valerian-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "This guide does not assess ingestion safety or medicinal use.",
"id": "red-valerian-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "red-valerian-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "red-valerian-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"red-valerian-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"red-valerian-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"red-valerian-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/red-valerian.md"
}
---
# Red valerian
*Centranthus ruber*
**Introduced drought-tolerant ornamental.** [N-centranthus-ruber](https://plants.ces.ncsu.edu/plants/centranthus-ruber/)
> **Self-seeds beyond garden beds.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The retrieved NC State source now treats Centranthus ruber as Valeriana rubra. The familiar garden name is retained for discovery; it is not Valeriana officinalis.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Upright stem with opposite smooth leaves and several pink-red flower clusters on a rocky slope.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centranthus_ruber_2_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c3/Centranthus_ruber_2_RF.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf and flower** — Smooth upright stem with opposite lance-shaped leaves and pink flower clusters in bud and bloom.
Photo: Christian Ferrer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centranthus_ruber,_S%C3%A8te_01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4d/Centranthus_ruber%2C_S%C3%A8te_01.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower and fruit** — White tubular flowers alongside a fruit with a spreading feathery plume.
Photo: Forest & Kim Starr; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Starr_030805-0035_Centranthus_ruber.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fd/Starr_030805-0035_Centranthus_ruber.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Clusters of small red, pink or white flowers above opposite, fleshy leaves. [N-centranthus-ruber](https://plants.ces.ncsu.edu/plants/centranthus-ruber/)
## Plants & habitat
Wind-dispersed seed can naturalize beyond a garden. Deadheading reduces spread; drought tolerance is not evidence that a plant is ecologically suitable everywhere. [N-centranthus-ruber](https://plants.ces.ncsu.edu/plants/centranthus-ruber/)
## People
This guide does not assess ingestion safety or medicinal use. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-centranthus-ruber** — [Centranthus ruber — Plant Toolbox](https://plants.ces.ncsu.edu/plants/centranthus-ruber/), NC State Extension. Accessed 2026-09-07T00:23:59+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=red-valerian) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
The retrieved NC State source now treats Centranthus ruber as Valeriana rubra. The familiar garden name is retained for discovery; it is not Valeriana officinalis.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| red-valerian-1 | Recognize | Species-specific | N-centranthus-ruber | No quantitative exposure threshold established here. |
| red-valerian-2 | Plants & habitat | Species-specific | N-centranthus-ruber | No quantitative exposure threshold established here. |
| red-valerian-3 | People | Review limitation | Review limitation | This guide does not assess ingestion safety or medicinal use. |
| red-valerian-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| red-valerian-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md
---
{
"id": "redroot-pigweed",
"name": "Redroot pigweed",
"scientific": "Amaranthus retroflexus",
"category": "invasive",
"status": "Common weed; not an A/B/C listing in the reviewed state rule",
"status_sources": [
"CO-rules-2025"
],
"warning": "Crop competition; nitrate and oxalate livestock risk",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "Pigweed is used for several unrelated or similar-looking plants. Routt County’s prostrate pigweed entry concerns A. blitoides and is not used as exact A. retroflexus evidence.",
"source_ids": [
"CO-rules-2025",
"N-amaranthus-retroflexus",
"C-descriptions",
"S27"
],
"description": "Redroot pigweed: Crop competition; nitrate and oxalate livestock risk. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-amaranthus-retroflexus"
],
"scope": "Species-specific",
"note": "",
"id": "redroot-pigweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-descriptions",
"N-amaranthus-retroflexus"
],
"scope": "Species-specific",
"note": "",
"id": "redroot-pigweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "redroot-pigweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "redroot-pigweed-4"
},
{
"label": "Other animals",
"sources": [
"N-amaranthus-retroflexus"
],
"scope": "Species-specific",
"note": "",
"id": "redroot-pigweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"redroot-pigweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"redroot-pigweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"redroot-pigweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/redroot-pigweed.md"
}
---
# Redroot pigweed
*Amaranthus retroflexus*
**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Crop competition; nitrate and oxalate livestock risk.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Pigweed is used for several unrelated or similar-looking plants. Routt County’s prostrate pigweed entry concerns A. blitoides and is not used as exact A. retroflexus evidence.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright plant with alternate broad leaves and a dense green terminal flower spike.
Photo: Lynk media; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Amaranthus_retroflexus_full1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/26/Amaranthus_retroflexus_full1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Several pigweed species are similar. These are source-identified A. retroflexus; an unknown specimen may require close floral and pubescence characters to separate related Amaranthus. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**inflorescence** — Dense branched green flower clusters above prominently veined leaves.
Photo: AnRo0002; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:20140822Amaranthus_retroflexus1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/89/20140822Amaranthus_retroflexus1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Several pigweed species are similar. These are source-identified A. retroflexus; an unknown specimen may require close floral and pubescence characters to separate related Amaranthus. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-stem** — Broad green leaves on long petioles beside a reddish upright stem.
Photo: Javier martin; [Public domain](https://commons.wikimedia.org/wiki/File:Amaranthus_retroflexus_HojasyTallos_2010-9-13_SierraMadrona.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Amaranthus_retroflexus_HojasyTallos_2010-9-13_SierraMadrona.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/82/Amaranthus_retroflexus_HojasyTallos_2010-9-13_SierraMadrona.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Several pigweed species are similar. These are source-identified A. retroflexus; an unknown specimen may require close floral and pubescence characters to separate related Amaranthus. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An upright annual with hairy stems and dense green flower clusters; the lower stem or root may be reddish. [N-amaranthus-retroflexus](https://plants.ces.ncsu.edu/plants/amaranthus-retroflexus/)
## Plants & habitat
A Colorado garden and field weed that competes strongly with crops and replenishes a seedbank. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-amaranthus-retroflexus](https://plants.ces.ncsu.edu/plants/amaranthus-retroflexus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Nitrate and oxalate accumulation can poison livestock. Conditions affect risk, so a plant’s appearance does not establish forage safety. [N-amaranthus-retroflexus](https://plants.ces.ncsu.edu/plants/amaranthus-retroflexus/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-amaranthus-retroflexus** — [amaranthus retroflexus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/amaranthus-retroflexus/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=redroot-pigweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Pigweed is used for several unrelated or similar-looking plants. Routt County’s prostrate pigweed entry concerns A. blitoides and is not used as exact A. retroflexus evidence.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| redroot-pigweed-1 | Recognize | Species-specific | N-amaranthus-retroflexus | No quantitative safe exposure established here. |
| redroot-pigweed-2 | Plants & habitat | Species-specific | C-descriptions, N-amaranthus-retroflexus | No quantitative safe exposure established here. |
| redroot-pigweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| redroot-pigweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| redroot-pigweed-5 | Other animals | Species-specific | N-amaranthus-retroflexus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/index.md
---
{
"id": "redstem-filaree",
"name": "Redstem filaree",
"scientific": "Erodium cicutarium",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Seeds spread through lawns and pasture",
"warning_tone": "caution",
"aliases": [
"stork’s bill",
"redstem storksbill"
],
"taxonomy_note": "The county’s unusually large height figure is not adopted. This guide relies on flower, rosette and fruit features instead.",
"source_ids": [
"CO-rules-2025",
"J-redstem-filaree",
"S27",
"Fremont-list-definitions"
],
"description": "Redstem filaree: Seeds spread through lawns and pasture. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-redstem-filaree"
],
"scope": "Species-specific",
"note": "",
"id": "redstem-filaree-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-redstem-filaree"
],
"scope": "Species-specific",
"note": "",
"id": "redstem-filaree-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "redstem-filaree-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "redstem-filaree-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "redstem-filaree-5"
},
{
"id": "redstem-filaree-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"redstem-filaree-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"redstem-filaree-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"redstem-filaree-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/redstem-filaree.md"
}
---
# Redstem filaree
*Erodium cicutarium*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Seeds spread through lawns and pasture.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The county’s unusually large height figure is not adopted. This guide relies on flower, rosette and fruit features instead.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruit** — Cluster of long narrow beaked fruits above divided foliage.
Photo: Follavoine / follavoine.net; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Erodium_cicutarium02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/3e/Erodium_cicutarium02.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit-foliage** — Low spreading plant with numerous finely divided fern-like leaves.
Photo: Follavoine / follavoine.net; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Erodium_cicutarium03.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0e/Erodium_cicutarium03.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Pink five-petaled flowers on slender stalks.
Photo: Michael H. Lemmer; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Erodium-cicutarium-250404.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/19/Erodium-cicutarium-250404.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A hairy rosette plant with pink-purple flowers and long-beaked fruits that develop corkscrew-like seed tails. [J-redstem-filaree](https://www.jeffco.us/2240/Redstem-Filaree)
## Plants & habitat
An introduced annual or biennial found in gardens, turf and disturbed land. Prevent seed spread and contain seed-bearing material. [J-redstem-filaree](https://www.jeffco.us/2240/Redstem-Filaree)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-redstem-filaree** — [Redstem Filaree](https://www.jeffco.us/2240/Redstem-Filaree), Jefferson County, Colorado. Accessed 2026-09-07T01:08:58+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=redstem-filaree) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The county’s unusually large height figure is not adopted. This guide relies on flower, rosette and fruit features instead.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| redstem-filaree-1 | Recognize | Species-specific | J-redstem-filaree | No quantitative safe exposure established here. |
| redstem-filaree-2 | Plants & habitat | Species-specific | J-redstem-filaree | No quantitative safe exposure established here. |
| redstem-filaree-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| redstem-filaree-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| redstem-filaree-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/index.md
---
{
"id": "rubber-rabbitbrush",
"name": "Rubber rabbitbrush",
"scientific": "Ericameria nauseosa",
"category": "xeriscape",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A native low-water shrub that can spread readily",
"warning_tone": "caution",
"aliases": [
"Chrysothamnus nauseosus",
"rabbitbrush"
],
"taxonomy_note": "Ericameria nauseosa was formerly Chrysothamnus nauseosus. A manufacturer entry for Chrysothamnus spp. is only partly represented by this profile; other rabbitbrush species remain separate research candidates.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"C-native-shrubs",
"F-ericameria",
"S27"
],
"description": "Rubber rabbitbrush: A native low-water shrub that can spread readily. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"C-native-shrubs"
],
"scope": "Species-specific",
"note": "",
"id": "rubber-rabbitbrush-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "rubber-rabbitbrush-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "rubber-rabbitbrush-3"
},
{
"label": "Other animals",
"sources": [
"F-ericameria"
],
"scope": "Older range synthesis; clinical details limited",
"note": "",
"id": "rubber-rabbitbrush-4"
},
{
"label": "Plants & habitat",
"sources": [
"C-native-shrubs"
],
"scope": "Species-specific",
"note": "",
"id": "rubber-rabbitbrush-5"
},
{
"label": "Management & timing",
"sources": [
"C-native-shrubs",
"F-ericameria"
],
"scope": "Landscape management synthesis",
"note": "",
"id": "rubber-rabbitbrush-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"rubber-rabbitbrush-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"rubber-rabbitbrush-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 51; Ericameria nauseosa",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Ericameria nauseosa"
},
"source": "content/plants/rubber-rabbitbrush.md"
}
---
# Rubber rabbitbrush
*Ericameria nauseosa*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A native low-water shrub that can spread readily.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Ericameria nauseosa was formerly Chrysothamnus nauseosus. A manufacturer entry for Chrysothamnus spp. is only partly represented by this profile; other rabbitbrush species remain separate research candidates.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Rubber rabbitbrush shrub with yellow flowering tips and pale branching stems in grassland.
Photo: Ian Adams; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/240399588); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/428289322/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers** — Close view of yellow tubular rubber rabbitbrush florets and the narrow green bracts surrounding the heads, against a black background.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/140188226); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/239930165/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves-stem** — Narrow rubber rabbitbrush leaves attached to a pale gray-green stem, photographed against a black background.
Photo: Douglas Goldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/); [source record](https://www.inaturalist.org/observations/140188226); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/239930554/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A rounded shrub with narrow aromatic leaves, green to silvery stems and clusters of yellow flowers late in the season. Size and appearance vary among varieties. [C-native-shrubs](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Wildlife browse it, especially seasonally. An older Forest Service synthesis also reports slight livestock toxicity; it does not provide pet-specific evidence or a validated safe ration. [F-ericameria](https://research.fs.usda.gov/feis/species-reviews/erinau)
*Evidence scope: Older range synthesis; clinical details limited.*
## Plants & habitat
CSU recommends it for native landscapes and notes that it can be aggressive. Late flowers attract butterflies; unwanted seedlings are a local garden-management issue. [C-native-shrubs](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/)
## Management & timing
Allow space for the mature shrub and watch for seedlings. Assess established native stands in their habitat context before removal. [C-native-shrubs](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/) [F-ericameria](https://research.fs.usda.gov/feis/species-reviews/erinau)
*Evidence scope: Landscape management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **C-native-shrubs** — [Native shrubs for Colorado landscapes](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/), Colorado State University Extension. Accessed 2026-09-07T02:33:44+00:00. Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions.
- **F-ericameria** — [Rubber rabbitbrush](https://research.fs.usda.gov/feis/species-reviews/erinau), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=rubber-rabbitbrush) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 51; Ericameria nauseosa. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Ericameria nauseosa was formerly Chrysothamnus nauseosus. A manufacturer entry for Chrysothamnus spp. is only partly represented by this profile; other rabbitbrush species remain separate research candidates.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| rubber-rabbitbrush-1 | Identification | Species-specific | C-native-shrubs | No quantitative safe exposure established here. |
| rubber-rabbitbrush-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| rubber-rabbitbrush-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| rubber-rabbitbrush-4 | Other animals | Older range synthesis; clinical details limited | F-ericameria | No quantitative safe exposure established here. |
| rubber-rabbitbrush-5 | Plants & habitat | Species-specific | C-native-shrubs | No quantitative safe exposure established here. |
| rubber-rabbitbrush-6 | Management & timing | Landscape management synthesis | C-native-shrubs, F-ericameria | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/index.md
---
{
"id": "rush-skeletonweed",
"name": "Rush skeletonweed",
"scientific": "Chondrilla juncea",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Deep roots and fragments sustain spread",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"WA-rush-skeletonweed",
"S27",
"Fremont-list-definitions"
],
"description": "Rush skeletonweed: Deep roots and fragments sustain spread. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-rush-skeletonweed"
],
"scope": "Species-specific",
"note": "",
"id": "rush-skeletonweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-rush-skeletonweed"
],
"scope": "Species-specific",
"note": "",
"id": "rush-skeletonweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "rush-skeletonweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "rush-skeletonweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "rush-skeletonweed-5"
},
{
"id": "rush-skeletonweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"rush-skeletonweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"rush-skeletonweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"rush-skeletonweed-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/rush-skeletonweed.md"
}
---
# Rush skeletonweed
*Chondrilla juncea*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Deep roots and fragments sustain spread.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower and buds** — A small yellow flower head beside narrow buds on nearly leafless branching stems.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/92807787); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/153840528/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**branching habit** — A widely branched, slender green shoot with sparse narrow leaves and a few yellow flowers.
Photo: KAnatoliy; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/87516388); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/144302465/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature habit** — A dense upright plant with many thin branches and small developing or spent heads.
Photo: KAnatoliy; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/87516388); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/144314499/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A basal rosette gives way to nearly leafless, branching stems with small yellow flowerheads. Lower stems have coarse, downward-pointing hairs. [WA-rush-skeletonweed](https://www.nwcb.wa.gov/weeds/rush-skeletonweed)
## Plants & habitat
Wind-carried seeds and root buds spread the plant. Deep roots and fragments can regenerate; infestations displace forage and native vegetation. [WA-rush-skeletonweed](https://www.nwcb.wa.gov/weeds/rush-skeletonweed)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-rush-skeletonweed** — [Rush Skeletonweed](https://www.nwcb.wa.gov/weeds/rush-skeletonweed), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:01+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=rush-skeletonweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| rush-skeletonweed-1 | Recognize | Species-specific | WA-rush-skeletonweed | No quantitative safe exposure established here. |
| rush-skeletonweed-2 | Plants & habitat | Species-specific | WA-rush-skeletonweed | No quantitative safe exposure established here. |
| rush-skeletonweed-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| rush-skeletonweed-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| rush-skeletonweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md
---
{
"id": "russian-knapweed",
"name": "Russian knapweed",
"scientific": "Rhaponticum repens",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-russian-knapweed"
],
"warning": "Toxic to horses",
"warning_tone": "danger",
"aliases": [
"Acroptilon repens",
"Centaurea repens"
],
"taxonomy_note": "The county page misspells the old genus as Arcoptilon; Acroptilon repens is the synonym used by NC State.",
"source_ids": [
"J-russian-knapweed",
"N-rhaponticum-repens",
"Fremont-list-definitions"
],
"description": "Russian knapweed: Toxic to horses. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-russian-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "russian-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-rhaponticum-repens",
"J-russian-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "russian-knapweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human ingestion effects were not established in this review.",
"id": "russian-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-rhaponticum-repens"
],
"scope": "Source tag; evidence detail limited",
"note": "",
"id": "russian-knapweed-4"
},
{
"label": "Other animals",
"sources": [
"N-rhaponticum-repens"
],
"scope": "Species-specific",
"note": "",
"id": "russian-knapweed-5"
},
{
"id": "russian-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"russian-knapweed-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/russian-knapweed.md"
}
---
# Russian knapweed
*Rhaponticum repens*
**Colorado noxious weed · List B — Stop the spread.** [J-russian-knapweed](https://www.jeffco.us/4107/Russian-knapweed)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Toxic to horses.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The county page misspells the old genus as Arcoptilon; Acroptilon repens is the synonym used by NC State.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**habit** — Dense patch of upright gray-green leafy plants beneath trees.
Photo: Amirh. absnd; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Acroptilon_repens_absnd.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/32/Acroptilon_repens_absnd.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Acroptilon repens and Rhaponticum repens are treated here as synonyms for Russian knapweed. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature-head** — Upright dry stems with pale tan mature heads and yellowing leaves.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Rhaponticum_repens_(5042408076).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/04/Rhaponticum_repens_%285042408076%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Acroptilon repens and Rhaponticum repens are treated here as synonyms for Russian knapweed. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Purple flower head above overlapping pale papery-tipped bracts, with narrow upper leaves.
Photo: Stan Shebs; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Rhaponticum_repens_4.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7f/Rhaponticum_repens_4.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source names Acroptilon repens and Rhaponticum repens are treated here as synonyms for Russian knapweed. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Pink to lavender heads with tan, papery bracts; creeping dark roots beneath a perennial stand. [J-russian-knapweed](https://www.jeffco.us/4107/Russian-knapweed)
## Plants & habitat
Spreading roots produce persistent colonies that displace native vegetation. Cutting alone does not resolve the deep root system. [N-rhaponticum-repens](https://plants.ces.ncsu.edu/plants/rhaponticum-repens/) [J-russian-knapweed](https://www.jeffco.us/4107/Russian-knapweed)
## People
Human ingestion effects were not established in this review. This is an evidence gap, not proof of safety.
## Dogs & cats
NC State tags the plant non-toxic to dogs and cats but provides no supporting pet assessment in its main text. We retain that limited claim without treating it as a safety clearance. [N-rhaponticum-repens](https://plants.ces.ncsu.edu/plants/rhaponticum-repens/)
## Other animals
Poisonous to horses. Keep it out of horse pasture and hay and contact a veterinarian after suspected ingestion. [N-rhaponticum-repens](https://plants.ces.ncsu.edu/plants/rhaponticum-repens/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-russian-knapweed** — [Russian knapweed](https://www.jeffco.us/4107/Russian-knapweed), Jefferson County, Colorado. Accessed 2026-09-07T00:27:24+00:00. Locator: Description, impacts, Colorado list designation, management.
- **N-rhaponticum-repens** — [Rhaponticum repens — Plant Toolbox](https://plants.ces.ncsu.edu/plants/rhaponticum-repens/), NC State Extension. Accessed 2026-09-07T00:24:01+00:00. Locator: Description, Attributes, Poisonous to Humans, Problems.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=russian-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
The county page misspells the old genus as Arcoptilon; Acroptilon repens is the synonym used by NC State.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| russian-knapweed-1 | Recognize | Species-specific | J-russian-knapweed | No quantitative exposure threshold established here. |
| russian-knapweed-2 | Plants & habitat | Species-specific | N-rhaponticum-repens, J-russian-knapweed | No quantitative exposure threshold established here. |
| russian-knapweed-3 | People | Review limitation | Review limitation | Human ingestion effects were not established in this review. |
| russian-knapweed-4 | Dogs & cats | Source tag; evidence detail limited | N-rhaponticum-repens | No quantitative exposure threshold established here. |
| russian-knapweed-5 | Other animals | Species-specific | N-rhaponticum-repens | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md
---
{
"id": "russian-olive",
"name": "Russian olive",
"scientific": "Elaeagnus angustifolia",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-russian-olive"
],
"warning": "Thorns; riparian habitat concern",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"J-russian-olive",
"Fremont-list-definitions"
],
"description": "Russian olive: Thorns; riparian habitat concern. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-russian-olive"
],
"scope": "Species-specific",
"note": "",
"id": "russian-olive-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-russian-olive"
],
"scope": "Species-specific",
"note": "",
"id": "russian-olive-2"
},
{
"label": "People",
"sources": [
"J-russian-olive"
],
"scope": "Physical-risk inference",
"note": "",
"id": "russian-olive-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-russian-olive"
],
"scope": "Physical-risk inference; toxicology gap",
"note": "",
"id": "russian-olive-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "russian-olive-5"
},
{
"id": "russian-olive-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"russian-olive-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"russian-olive-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/russian-olive.md"
}
---
# Russian olive
*Elaeagnus angustifolia*
**Colorado noxious weed · List B — Stop the spread.** [J-russian-olive](https://www.jeffco.us/2224/Russian-Olive)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Thorns; riparian habitat concern.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower-leaf** — Small yellow flowers and narrow silvery leaves on a twig.
Photo: Georg Slickers; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Elaeagnus_angustifolia_20050608_852.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f0/Elaeagnus_angustifolia_20050608_852.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**fruit-leaf** — Oval pale fruits hanging among narrow leaves with silvery surfaces.
Photo: Georg Slickers; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Elaeagnus_angustifolia_20050905_942.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/fa/Elaeagnus_angustifolia_20050905_942.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Mature tree with a branching dark trunk and a spreading silvery-green crown.
Photo: Sten Porse; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Elaeagnus-angustifolia-habit.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f2/Elaeagnus-angustifolia-habit.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A woody shrub or tree with narrow, silvery leaves, fragrant yellow flowers and olive-shaped fruits. Branches may bear long thorns. [J-russian-olive](https://www.jeffco.us/2224/Russian-Olive)
## Plants & habitat
An introduced plant of riparian areas and old windbreaks. Stumps, roots and discarded twigs can regrow; plan removal and follow-up together. [J-russian-olive](https://www.jeffco.us/2224/Russian-Olive)
## People
Thorns can puncture skin and eyes. Protective handling is a physical-risk precaution; this profile does not assess fruit consumption. [J-russian-olive](https://www.jeffco.us/2224/Russian-Olive)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Thorny branches can injure animals. Pet-specific chemical toxicity is not established in this review. [J-russian-olive](https://www.jeffco.us/2224/Russian-Olive)
*Evidence scope: Physical-risk inference; toxicology gap.*
## Other animals
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-russian-olive** — [Russian Olive](https://www.jeffco.us/2224/Russian-Olive), Jefferson County, Colorado. Accessed 2026-09-07T00:27:25+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=russian-olive) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| russian-olive-1 | Recognize | Species-specific | J-russian-olive | No quantitative exposure threshold established here. |
| russian-olive-2 | Plants & habitat | Species-specific | J-russian-olive | No quantitative exposure threshold established here. |
| russian-olive-3 | People | Physical-risk inference | J-russian-olive | No quantitative exposure threshold established here. |
| russian-olive-4 | Dogs & cats | Physical-risk inference; toxicology gap | J-russian-olive | No quantitative exposure threshold established here. |
| russian-olive-5 | Other animals | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/index.md
---
{
"id": "russian-sage",
"name": "Russian sage",
"scientific": "Salvia yangii",
"category": "xeriscape",
"status": "Introduced low-water garden perennial",
"status_sources": [
"N-russian-sage",
"C-russian-sage"
],
"warning": "Spreads by suckers; pet evidence unresolved",
"warning_tone": "caution",
"aliases": [
"Perovskia atriplicifolia"
],
"taxonomy_note": "NC State uses Salvia yangii; older Colorado guidance uses Perovskia atriplicifolia. The older statement that this plant is outside Salvia is outdated. Culinary sage (Salvia officinalis) safety claims do not apply automatically.",
"source_ids": [
"N-russian-sage",
"C-russian-sage",
"E-sage-suckers",
"S27"
],
"description": "Russian sage: Spreads by suckers; pet evidence unresolved. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-russian-sage"
],
"scope": "Species-specific",
"note": "",
"id": "russian-sage-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-russian-sage",
"E-sage-suckers"
],
"scope": "Horticultural evidence; county extension advice",
"note": "",
"id": "russian-sage-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "russian-sage-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "russian-sage-4"
},
{
"label": "Other animals",
"sources": [
"N-russian-sage"
],
"scope": "Species-specific",
"note": "",
"id": "russian-sage-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"russian-sage-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"russian-sage-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/russian-sage.md"
}
---
# Russian sage
*Salvia yangii*
**Introduced low-water garden perennial.** [N-russian-sage](https://plants.ces.ncsu.edu/plants/salvia-yangii/) [C-russian-sage](https://planttalk.colostate.edu/topics/annuals-perennials/1050-russian-sage/)
> **Spreads by suckers; pet evidence unresolved.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** NC State uses Salvia yangii; older Colorado guidance uses Perovskia atriplicifolia. The older statement that this plant is outside Salvia is outdated. Culinary sage (Salvia officinalis) safety claims do not apply automatically.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**leaf** — Gray-green deeply divided leaves arranged in opposite pairs on a pale stem.
Photo: Doronenko; [CC BY 2.5](https://creativecommons.org/licenses/by/2.5); [source record](https://commons.wikimedia.org/wiki/File:Perovskia_atriplicifolia_leave.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/bd/Perovskia_atriplicifolia_leave.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Perovskia atriplicifolia is the synonym used on these source pages. Garden photographs do not establish cultivar identity or exclude hybrid ancestry; captions use the source-identified species. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Small violet-blue flowers with pale hairy calyces cluster around a slender flowering stem.
Photo: AnRo0002; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:20170719Perovskia_atriplicifolia1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f3/20170719Perovskia_atriplicifolia1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Perovskia atriplicifolia is the synonym used on these source pages. Garden photographs do not establish cultivar identity or exclude hybrid ancestry; captions use the source-identified species. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Many pale branched stems with deeply cut gray-green leaves and scattered violet-blue flowers form a loose leafy clump.
Photo: David J. Stang; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Perovskia_atriplicifolia_0zz.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/1e/Perovskia_atriplicifolia_0zz.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Perovskia atriplicifolia is the synonym used on these source pages. Garden photographs do not establish cultivar identity or exclude hybrid ancestry; captions use the source-identified species. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A woody-based perennial with silvery, aromatic, finely divided leaves and airy purple flower spikes. The stems are square. [N-russian-sage](https://plants.ces.ncsu.edu/plants/salvia-yangii/)
## Plants & habitat
An introduced plant suited to sunny, well-drained Colorado gardens. Shoots can spread beyond the original clump by suckers; remove unwanted shoots and allow room at bed edges. [C-russian-sage](https://planttalk.colostate.edu/topics/annuals-perennials/1050-russian-sage/) [E-sage-suckers](https://ask.extension.org/kb/faq.php?id=639127)
*Evidence scope: Horticultural evidence; county extension advice.*
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Flowers attract pollinators. Reported deer and rabbit resistance is not evidence of livestock or pet feeding safety. [N-russian-sage](https://plants.ces.ncsu.edu/plants/salvia-yangii/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **N-russian-sage** — [Russian sage (Salvia yangii)](https://plants.ces.ncsu.edu/plants/salvia-yangii/), NC State Extension. Accessed 2026-09-07T00:57:24+00:00. Locator: Description, synonyms, native range, wildlife value.
- **C-russian-sage** — [1050: Russian Sage](https://planttalk.colostate.edu/topics/annuals-perennials/1050-russian-sage/), Colorado State University Extension / PlantTalk. Accessed 2026-09-07T00:57:25+00:00. Locator: Colorado garden use; taxonomy sentence is outdated relative to NC State.
- **E-sage-suckers** — [Russian Sage Suckers](https://ask.extension.org/kb/faq.php?id=639127), Ask Extension. Accessed 2026-09-07T00:57:24+00:00. Locator: Expert response on sucker growth.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=russian-sage) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
NC State uses Salvia yangii; older Colorado guidance uses Perovskia atriplicifolia. The older statement that this plant is outside Salvia is outdated. Culinary sage (Salvia officinalis) safety claims do not apply automatically.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| russian-sage-1 | Recognize | Species-specific | N-russian-sage | No quantitative safe exposure established here. |
| russian-sage-2 | Plants & habitat | Horticultural evidence; county extension advice | C-russian-sage, E-sage-suckers | No quantitative safe exposure established here. |
| russian-sage-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| russian-sage-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| russian-sage-5 | Other animals | Species-specific | N-russian-sage | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md
---
{
"id": "russian-thistle",
"name": "Russian thistle",
"scientific": "Salsola tragus",
"category": "invasive",
"status": "Introduced annual weed; not designated on the reviewed Colorado A/B/C lists",
"status_sources": [
"C-tumbleweeds",
"CO-rules-2025"
],
"warning": "Prickly tumbleweeds; livestock and fire hazards",
"warning_tone": "danger",
"aliases": [
"tumbleweed",
"Kali tragus",
"prickly Russian thistle"
],
"taxonomy_note": "Russian thistle is a common name for several similar Salsola taxa. This profile uses S. tragus as its principal name; UC’s identification and dry-plant hazards address a species complex. A round tumbleweed alone does not establish the species.",
"source_ids": [
"C-tumbleweeds",
"CO-rules-2025",
"UC-russian-thistle",
"S27"
],
"description": "Russian thistle: Prickly tumbleweeds; livestock and fire hazards. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"UC-russian-thistle"
],
"scope": "Russian-thistle species complex",
"note": "",
"id": "russian-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"UC-russian-thistle",
"C-tumbleweeds"
],
"scope": "Species-group hazards; editorial prevention priority",
"note": "",
"id": "russian-thistle-2"
},
{
"label": "People",
"sources": [
"UC-russian-thistle"
],
"scope": "Physical-risk inference",
"note": "",
"id": "russian-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"UC-russian-thistle"
],
"scope": "Physical-risk inference; pet toxicology gap",
"note": "",
"id": "russian-thistle-4"
},
{
"label": "Other animals",
"sources": [
"C-tumbleweeds"
],
"scope": "Species-specific",
"note": "",
"id": "russian-thistle-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"russian-thistle-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/russian-thistle.md"
}
---
# Russian thistle
*Salsola tragus*
**Introduced annual weed; not designated on the reviewed Colorado A/B/C lists.** [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Prickly tumbleweeds; livestock and fire hazards.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Russian thistle is a common name for several similar Salsola taxa. This profile uses S. tragus as its principal name; UC’s identification and dry-plant hazards address a species complex. A round tumbleweed alone does not establish the species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Rounded, densely branched green plant with slender leaves and spiny-looking branch tips.
Photo: Stefan.lefnaer; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Salsola_tragus_sl7.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/41/Salsola_tragus_sl7.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Russian thistle is a species complex, and related Salsola/Kali taxa can form similar tumbleweeds. These are source-identified Salsola tragus/Kali tragus reference photographs; a dry tumbleweed or general habit photograph alone cannot establish species identity. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature-fruiting-branches** — Rows of pink-red papery fruiting structures line branching stems among narrow green leaves.
Photo: Jim Pisarowicz; [Public domain](https://commons.wikimedia.org/wiki/File:Kali_tragus_NPS-1.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Kali_tragus_NPS-1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/ca/Kali_tragus_NPS-1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Russian thistle is a species complex, and related Salsola/Kali taxa can form similar tumbleweeds. These are source-identified Salsola tragus/Kali tragus reference photographs; a dry tumbleweed or general habit photograph alone cannot establish species identity. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**dried-form** — Dry pale-brown branching plant with persistent spiny bracts and small papery fruiting structures.
Photo: Stefan.lefnaer; [CC BY-SA 3.0 at](https://creativecommons.org/licenses/by-sa/3.0/at/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Kali_tragus_sl10.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/cf/Kali_tragus_sl10.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Russian thistle is a species complex, and related Salsola/Kali taxa can form similar tumbleweeds. These are source-identified Salsola tragus/Kali tragus reference photographs; a dry tumbleweed or general habit photograph alone cannot establish species identity. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A branching annual that becomes rounded and prickly. Mature leaves and bracts have stiff tips; stems often show reddish stripes. Dry plants can detach and tumble. [UC-russian-thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/)
*Evidence scope: Russian-thistle species complex.*
## Plants & habitat
Invades disturbed ground. Dry accumulations can obstruct traffic and create a fire hazard; prevent seed production before plants detach. [UC-russian-thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/) [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/)
*Evidence scope: Species-group hazards; editorial prevention priority.*
## People
Stiff, sharp parts can puncture skin. Wear sturdy gloves when handling dry plants; this is a physical-risk inference, not a human poison diagnosis. [UC-russian-thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Prickly material may injure paws or mouths. The reviewed livestock findings do not establish a pet toxic dose. Keep pets away from dry piles. [UC-russian-thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/)
*Evidence scope: Physical-risk inference; pet toxicology gap.*
## Other animals
CSU reports nitrate and oxalate poisoning risks for cattle and sheep, including severe breathing problems or kidney damage. Do not assume this weed is suitable forage. [C-tumbleweeds](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-tumbleweeds** — [Identification and Management of Kochia and Russian Thistle](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/), Colorado State University Extension. Accessed 2026-09-07T00:57:25+00:00. Locator: Weed Description; Livestock Poisonings; Integrated Weed Management.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **UC-russian-thistle** — [Russian Thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/), University of California Statewide IPM. Accessed 2026-09-07T00:57:25+00:00. Locator: Taxonomic complex, morphology, oxalates, dry tumbleweed hazards.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=russian-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Russian thistle is a common name for several similar Salsola taxa. This profile uses S. tragus as its principal name; UC’s identification and dry-plant hazards address a species complex. A round tumbleweed alone does not establish the species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| russian-thistle-1 | Recognize | Russian-thistle species complex | UC-russian-thistle | No quantitative safe exposure established here. |
| russian-thistle-2 | Plants & habitat | Species-group hazards; editorial prevention priority | UC-russian-thistle, C-tumbleweeds | No quantitative safe exposure established here. |
| russian-thistle-3 | People | Physical-risk inference | UC-russian-thistle | No quantitative safe exposure established here. |
| russian-thistle-4 | Dogs & cats | Physical-risk inference; pet toxicology gap | UC-russian-thistle | No quantitative safe exposure established here. |
| russian-thistle-5 | Other animals | Species-specific | C-tumbleweeds | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/index.md
---
{
"id": "scentless-chamomile",
"name": "Scentless chamomile",
"scientific": "Tripleurospermum inodorum",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Prolific seeds; reported livestock irritation",
"warning_tone": "caution",
"aliases": [
"scentless mayweed",
"Matricaria perforata"
],
"taxonomy_note": "Not interchangeable with Roman chamomile, German chamomile or mayweed chamomile. Their poison and food-use records require exact name matching.",
"source_ids": [
"CO-rules-2025",
"J-scentless-chamomile",
"S27",
"Fremont-list-definitions"
],
"description": "Scentless chamomile: Prolific seeds; reported livestock irritation. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-scentless-chamomile"
],
"scope": "Species-specific",
"note": "",
"id": "scentless-chamomile-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-scentless-chamomile"
],
"scope": "Species-specific",
"note": "",
"id": "scentless-chamomile-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "scentless-chamomile-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "scentless-chamomile-4"
},
{
"label": "Other animals",
"sources": [
"J-scentless-chamomile"
],
"scope": "Species-specific",
"note": "",
"id": "scentless-chamomile-5"
},
{
"id": "scentless-chamomile-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"scentless-chamomile-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"scentless-chamomile-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/scentless-chamomile.md"
}
---
# Scentless chamomile
*Tripleurospermum inodorum*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Prolific seeds; reported livestock irritation.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Not interchangeable with Roman chamomile, German chamomile or mayweed chamomile. Their poison and food-use records require exact name matching.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — A low branching scentless-chamomile plant with many white-and-yellow flower heads on bare ground.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Tripleurospermum_inodorum_kz13.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f3/Tripleurospermum_inodorum_kz13.jpg). Source-identified photograph with visual consistency check Tripleurospermum inodorum in Lubanowo near Banie, NW Poland Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seedling** — A scentless-chamomile seedling with elongated cotyledons and its first divided leaves in bare soil.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Tripleurospermum_inodorum_kz11.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c5/Tripleurospermum_inodorum_kz11.jpg). Source-identified photograph with visual consistency check Tripleurospermum inodorum seedling, Przęsocin near Szczecin, NW Poland Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage** — A close view of finely divided, threadlike scentless-chamomile leaves on a stem.
Photo: Rob Hille; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Tripleurospermum_inodorum_RH_(18).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8f/Tripleurospermum_inodorum_RH_%2818%29.jpg). Source-identified photograph with visual consistency check Tripleurospermum inodorum Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
White ray flowers surround a yellow center above finely divided, nearly odorless leaves. [J-scentless-chamomile](https://www.jeffco.us/2205/Scentless-Chamomile)
## Plants & habitat
Dense seedlings develop in meadows and disturbed ground. Many persistent seeds and regrowth after mowing complicate control. [J-scentless-chamomile](https://www.jeffco.us/2205/Scentless-Chamomile)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The county reports possible blistering in livestock but provides limited clinical detail. Do not assume unrestricted grazing is safe. [J-scentless-chamomile](https://www.jeffco.us/2205/Scentless-Chamomile)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **J-scentless-chamomile** — [Scentless Chamomile](https://www.jeffco.us/2205/Scentless-Chamomile), Jefferson County, Colorado. Accessed 2026-09-07T01:08:59+00:00. Locator: Species description and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=scentless-chamomile) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Not interchangeable with Roman chamomile, German chamomile or mayweed chamomile. Their poison and food-use records require exact name matching.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| scentless-chamomile-1 | Recognize | Species-specific | J-scentless-chamomile | No quantitative safe exposure established here. |
| scentless-chamomile-2 | Plants & habitat | Species-specific | J-scentless-chamomile | No quantitative safe exposure established here. |
| scentless-chamomile-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| scentless-chamomile-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| scentless-chamomile-5 | Other animals | Species-specific | J-scentless-chamomile | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/index.md
---
{
"id": "scotch-thistle",
"name": "Scotch thistle",
"scientific": "Onopordum acanthium",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-scotch-thistle"
],
"warning": "Sharp spines; competes with vegetation",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.",
"source_ids": [
"J-scotch-thistle",
"Fremont-list-definitions"
],
"description": "Scotch thistle: Sharp spines; competes with vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-scotch-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "scotch-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-scotch-thistle"
],
"scope": "Species-specific",
"note": "",
"id": "scotch-thistle-2"
},
{
"label": "People",
"sources": [
"J-scotch-thistle"
],
"scope": "Physical-risk inference from documented spines",
"note": "",
"id": "scotch-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"J-scotch-thistle"
],
"scope": "Physical-risk inference; toxicology gap",
"note": "",
"id": "scotch-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "The reviewed control source does not establish species-specific livestock chemical toxicity.",
"id": "scotch-thistle-5"
},
{
"id": "scotch-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"scotch-thistle-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"scotch-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/scotch-thistle.md"
}
---
# Scotch thistle
*Onopordum acanthium*
**Colorado noxious weed · List B — Stop the spread.** [J-scotch-thistle](https://www.jeffco.us/2192/Scotch-Thistle)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; competes with vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**leaf** — Pale woolly young leaf with deeply lobed spine-tipped margins and a prominent light midrib.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Onopordum_acanthium_kz14.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f5/Onopordum_acanthium_kz14.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. None; original downloaded without modification. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Upright branched thistle with large pale spiny leaves and purple flower heads.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Onopordum_acanthium_kz15.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e0/Onopordum_acanthium_kz15.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**bud-stem** — Developing spiny heads on pale winged stems; narrow rigid bracts end in yellowish spines.
Photo: Benutzer:Drahkrub; [CC BY-SA 3.0 de](https://creativecommons.org/licenses/by-sa/3.0/de/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Onopordum_acanthium-Detail.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/ef/Onopordum_acanthium-Detail.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. None; original downloaded without modification. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A large, woolly biennial with broad leaves, purple heads and conspicuous spiny stem wings. [J-scotch-thistle](https://www.jeffco.us/2192/Scotch-Thistle)
## Plants & habitat
Can form dense rosettes and persist through a long-lived seed bank. Maintain competing vegetation and prevent seed production. [J-scotch-thistle](https://www.jeffco.us/2192/Scotch-Thistle)
## People
Spines can puncture skin. Sturdy gloves are a practical precaution when handling; confirm identification before removing a thistle. [J-scotch-thistle](https://www.jeffco.us/2192/Scotch-Thistle)
*Evidence scope: Physical-risk inference from documented spines.*
## Dogs & cats
Spiny material can injure paws or mouths. Species-specific chemical toxicity is unresolved in this review. [J-scotch-thistle](https://www.jeffco.us/2192/Scotch-Thistle)
*Evidence scope: Physical-risk inference; toxicology gap.*
## Other animals
The reviewed control source does not establish species-specific livestock chemical toxicity. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-scotch-thistle** — [Scotch Thistle](https://www.jeffco.us/2192/Scotch-Thistle), Jefferson County, Colorado. Accessed 2026-09-07T00:27:26+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=scotch-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Colorado also has native thistles. Purple flowers and spines alone cannot distinguish a listed introduced species.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| scotch-thistle-1 | Recognize | Species-specific | J-scotch-thistle | No quantitative exposure threshold established here. |
| scotch-thistle-2 | Plants & habitat | Species-specific | J-scotch-thistle | No quantitative exposure threshold established here. |
| scotch-thistle-3 | People | Physical-risk inference from documented spines | J-scotch-thistle | No quantitative exposure threshold established here. |
| scotch-thistle-4 | Dogs & cats | Physical-risk inference; toxicology gap | J-scotch-thistle | No quantitative exposure threshold established here. |
| scotch-thistle-5 | Other animals | Review limitation | Review limitation | The reviewed control source does not establish species-specific livestock chemical toxicity. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/index.md
---
{
"id": "shepherds-purse",
"name": "Shepherd’s purse",
"scientific": "Capsella bursa-pastoris",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "An early-seeding lawn and garden weed",
"warning_tone": "caution",
"aliases": [
"shepherd's purse"
],
"taxonomy_note": "",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-capsella-bursa-pastoris",
"C-descriptions",
"S27"
],
"description": "Shepherd’s purse: An early-seeding lawn and garden weed. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-capsella-bursa-pastoris"
],
"scope": "Species-specific",
"note": "",
"id": "shepherds-purse-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "shepherds-purse-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "shepherds-purse-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "shepherds-purse-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-capsella-bursa-pastoris"
],
"scope": "Species-specific",
"note": "",
"id": "shepherds-purse-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "shepherds-purse-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"shepherds-purse-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"shepherds-purse-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"shepherds-purse-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 41; Capsella bursa‐pastoris",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Capsella bursa‐pastoris"
},
"source": "content/plants/shepherds-purse.md"
}
---
# Shepherd’s purse
*Capsella bursa-pastoris*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **An early-seeding lawn and garden weed.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**rosette** — A flat basal rosette of deeply lobed leaves spreads over bare soil.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Herderstasje_bladrozet_(Capsella_bursa-pastoris).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/95/Herderstasje_bladrozet_%28Capsella_bursa-pastoris%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. bursa-pastoris. Rosette leaves vary greatly and overlap other mustards; the distinctive fruits and floral characters provide stronger identification than rosette shape alone. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — Whole plant laid against a plain surface, with a basal rosette and slender branching flowering stalks.
Photo: Forest & Kim Starr; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Starr_070308-5329_Capsella_bursa-pastoris.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/84/Starr_070308-5329_Capsella_bursa-pastoris.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. bursa-pastoris. Rosette leaves vary greatly and overlap other mustards; the distinctive fruits and floral characters provide stronger identification than rosette shape alone. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruit-flower** — Triangular heart-shaped green pods line a slender stem below small white flowers.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Capsella_bursa-pastoris_002.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2d/Capsella_bursa-pastoris_002.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified C. bursa-pastoris. Rosette leaves vary greatly and overlap other mustards; the distinctive fruits and floral characters provide stronger identification than rosette shape alone. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A small annual mustard with a basal leaf rosette, tiny white flowers and flat, heart-shaped or triangular seedpods. Seedlings can establish in spring or autumn. [N-capsella-bursa-pastoris](https://plants.ces.ncsu.edu/plants/capsella-bursa-pastoris/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It readily colonizes disturbed ground and reseeds in gardens and roadsides. Drought and compaction tolerance help it persist. [N-capsella-bursa-pastoris](https://plants.ces.ncsu.edu/plants/capsella-bursa-pastoris/)
## Management & timing
Pull or hoe before the distinctive pods mature. Check again after another flush of seedlings. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-capsella-bursa-pastoris** — [Capsella bursa pastoris](https://plants.ces.ncsu.edu/plants/capsella-bursa-pastoris/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=shepherds-purse) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 41; Capsella bursa‐pastoris. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| shepherds-purse-1 | Identification | Species-specific | N-capsella-bursa-pastoris | No quantitative safe exposure established here. |
| shepherds-purse-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| shepherds-purse-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| shepherds-purse-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| shepherds-purse-5 | Plants & habitat | Species-specific | N-capsella-bursa-pastoris | No quantitative safe exposure established here. |
| shepherds-purse-6 | Management & timing | Species-specific | C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md
---
{
"id": "showy-milkweed",
"name": "Showy milkweed",
"scientific": "Asclepias speciosa",
"category": "native",
"status": "Colorado native",
"status_sources": [
"S02",
"S28"
],
"warning": "Toxic if eaten",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S02",
"S28",
"S03",
"S05",
"S04"
],
"description": "Showy milkweed: Toxic if eaten. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S03"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "showy-milkweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"S02"
],
"scope": "Species-specific + garden judgment",
"note": "Crowding advice is an editorial inference from self-seeding, not a measured allelopathy claim.",
"reviewed": "2026-09-06",
"id": "showy-milkweed-2"
},
{
"label": "People",
"sources": [
"S05"
],
"scope": "Genus-level",
"note": "",
"reviewed": "2026-09-06",
"id": "showy-milkweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"S04"
],
"scope": "Genus-level",
"note": "",
"reviewed": "2026-09-06",
"id": "showy-milkweed-4"
},
{
"label": "Other animals",
"sources": [
"S04",
"S02"
],
"scope": "Genus-level toxicity; species-specific benefit",
"note": "",
"reviewed": "2026-09-06",
"id": "showy-milkweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/showy-milkweed.md"
}
---
# Showy milkweed
*Asclepias speciosa*
**Colorado native.** [S02](https://pueblo.extension.colostate.edu/low-water-native-plants-for-pollinators/) [S28](https://pueblo.extension.colostate.edu/loving-our-native-plants/)
> **Toxic if eaten.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flowers** — Close view of pale pink showy milkweed flowers, with long pointed hoods above reflexed petals.
Photo: Andrey Zharkikh; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Asclepias_speciosa,_Red_Butte,_Utah.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/93/Asclepias_speciosa%2C_Red_Butte%2C_Utah.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers** — Pink and white showy milkweed flower cluster viewed from above, showing pointed hoods and unopened buds.
Photo: Tom Koerner / U.S. Fish and Wildlife Service; [Public domain](https://commons.wikimedia.org/wiki/Template:PD-USGov-FWS); [source record](https://commons.wikimedia.org/wiki/File:Asclepias_speciosa_at_Seedskadee_NWR_94_(48714355833).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0d/Asclepias_speciosa_at_Seedskadee_NWR_94_%2848714355833%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seed pod** — An open, rough-surfaced milkweed pod releasing brown seeds with silky white hairs.
Photo: John Rusk from Berkeley, CA, United States of America; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:H20120920-5647%E2%80%94Asclepias_speciosa%E2%80%94RPBG_(9520794890).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6c/H20120920-5647%E2%80%94Asclepias_speciosa%E2%80%94RPBG_%289520794890%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Pink flower clusters on an upright perennial; included in the Front Range native plant guide. [S03](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf)
## Plants & habitat
Self-seeds and supports monarch caterpillars. Garden judgment: give volunteers room or manage seedlings beside smaller plants. [S02](https://pueblo.extension.colostate.edu/low-water-native-plants-for-pollinators/)
## People
Milkweed ingestion can cause serious poisoning; sap may irritate skin and eyes. Wear gloves when handling. [S05](https://www.poison.org/articles/milkweed-can-cause-serious-poisoning-204)
*Evidence scope: Genus-level.*
## Dogs & cats
Milkweeds are toxic to both. Signs can include vomiting and weakness, with potentially severe effects. Contact a veterinarian promptly after suspected ingestion. [S04](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed)
*Evidence scope: Genus-level.*
## Other animals
Milkweeds can poison horses and other livestock, while monarch caterpillars use this species as food. [S04](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed) [S02](https://pueblo.extension.colostate.edu/low-water-native-plants-for-pollinators/)
*Evidence scope: Genus-level toxicity; species-specific benefit.*
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S02** — [Low Water Native Plants for Pollinators](https://pueblo.extension.colostate.edu/low-water-native-plants-for-pollinators/), CSU Extension · Pueblo County. Accessed 2026-09-07T00:23:52+00:00. Locator: Mid-Season Wildflowers: Showy Milkweed.
- **S28** — [Loving Our Native Plants](https://pueblo.extension.colostate.edu/loving-our-native-plants/), CSU Extension · Pueblo County. Accessed 2026-09-07T00:23:56+00:00. Locator: Native landscape plant list: Common sunflower and Showy milkweed.
- **S03** — [Low-Water Native Plants for Colorado Gardens: Front Range & Foothills](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf), Colorado Native Plant Society / CSU Extension. Accessed 2026-09-07T00:23:53+00:00. Locator: Plant table: Asclepias speciosa and Achillea millefolium.
- **S05** — [Milkweed plants can cause serious poisoning](https://www.poison.org/articles/milkweed-can-cause-serious-poisoning-204), National Capital Poison Center. Accessed 2026-09-07T00:23:53+00:00. Locator: Symptoms; Effects on skin and in eyes; prevention.
- **S04** — [Milkweed](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed), ASPCA Poison Control. Accessed 2026-09-07T00:23:52+00:00. Locator: Scientific Name; Toxicity; Clinical Signs; poison contact.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=showy-milkweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| showy-milkweed-1 | Recognize | Species-specific | S03 | No quantitative exposure threshold established here. |
| showy-milkweed-2 | Plants & habitat | Species-specific + garden judgment | S02 | Crowding advice is an editorial inference from self-seeding, not a measured allelopathy claim. |
| showy-milkweed-3 | People | Genus-level | S05 | No quantitative exposure threshold established here. |
| showy-milkweed-4 | Dogs & cats | Genus-level | S04 | No quantitative exposure threshold established here. |
| showy-milkweed-5 | Other animals | Genus-level toxicity; species-specific benefit | S04, S02 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/index.md
---
{
"id": "siberian-elm",
"name": "Siberian elm",
"scientific": "Ulmus pumila",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Numerous seedlings; weak branches",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Weak-wood descriptions support the structural concern; this guide cannot assess the stability of an individual tree.",
"source_ids": [
"CO-rules-2025",
"N-ulmus-pumila",
"S27",
"Fremont-list-definitions"
],
"description": "Siberian elm: Numerous seedlings; weak branches. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-ulmus-pumila"
],
"scope": "Species-specific",
"note": "",
"id": "siberian-elm-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-ulmus-pumila"
],
"scope": "Species-specific",
"note": "",
"id": "siberian-elm-2"
},
{
"label": "People",
"sources": [
"N-ulmus-pumila"
],
"scope": "Species-specific",
"note": "",
"id": "siberian-elm-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-ulmus-pumila"
],
"scope": "Species-specific",
"note": "",
"id": "siberian-elm-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "siberian-elm-5"
},
{
"id": "siberian-elm-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"siberian-elm-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"siberian-elm-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/siberian-elm.md"
}
---
# Siberian elm
*Ulmus pumila*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Numerous seedlings; weak branches.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Weak-wood descriptions support the structural concern; this guide cannot assess the stability of an individual tree.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**samaras** — Clusters of pale green round winged fruits on a twig.
Photo: Shizhao; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Elm_in_beijing.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/2/21/Elm_in_beijing.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Small green serrated leaves with strongly impressed side veins.
Photo: Melburnian; [CC BY 2.5](https://creativecommons.org/licenses/by/2.5); [source record](https://commons.wikimedia.org/wiki/File:Ulmus_pumila_leaves.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5b/Ulmus_pumila_leaves.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Mature leafy tree with an upright trunk and spreading irregular crown.
Photo: Dalgial; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:%EB%B9%84%EC%88%A0%EB%82%98%EB%AC%B4.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c8/%EB%B9%84%EC%88%A0%EB%82%98%EB%AC%B4.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Elms can hybridize and have similar foliage. These are source-identified U. pumila photographs; cultivar identity or hybrid ancestry is not determined. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A deciduous tree with small, toothed leaves and round, papery winged fruits in spring. [N-ulmus-pumila](https://plants.ces.ncsu.edu/plants/ulmus-pumila/)
## Plants & habitat
Abundant seeds create colonies in disturbed ground and grasslands; small seedlings are easier to manage than established trees. [N-ulmus-pumila](https://plants.ces.ncsu.edu/plants/ulmus-pumila/)
## People
Weak wood and branches are a structural concern. Have a qualified arborist assess large trees near occupied areas. [N-ulmus-pumila](https://plants.ces.ncsu.edu/plants/ulmus-pumila/)
## Dogs & cats
Falling limbs can endanger animals as well as people; this is a structural-risk inference. Pet ingestion effects are unresolved. [N-ulmus-pumila](https://plants.ces.ncsu.edu/plants/ulmus-pumila/)
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-ulmus-pumila** — [ulmus pumila — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ulmus-pumila/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=siberian-elm) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Weak-wood descriptions support the structural concern; this guide cannot assess the stability of an individual tree.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| siberian-elm-1 | Recognize | Species-specific | N-ulmus-pumila | No quantitative safe exposure established here. |
| siberian-elm-2 | Plants & habitat | Species-specific | N-ulmus-pumila | No quantitative safe exposure established here. |
| siberian-elm-3 | People | Species-specific | N-ulmus-pumila | No quantitative safe exposure established here. |
| siberian-elm-4 | Dogs & cats | Species-specific | N-ulmus-pumila | No quantitative safe exposure established here. |
| siberian-elm-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md
---
{
"id": "silverleaf-nightshade",
"name": "Silverleaf nightshade",
"scientific": "Solanum elaeagnifolium",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Toxic leaves and berries; persistent spreading roots",
"warning_tone": "danger",
"aliases": [
"silver-leaved nightshade"
],
"taxonomy_note": "Distinct from buffalobur, horsenettle and black nightshade species. Native status does not imply harmlessness or prevent it being invasive outside its native range.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"U-silverleaf",
"S27"
],
"description": "Silverleaf nightshade: Toxic leaves and berries; persistent spreading roots. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"U-silverleaf"
],
"scope": "Species-specific",
"note": "",
"id": "silverleaf-nightshade-1"
},
{
"label": "People",
"sources": [
"U-silverleaf"
],
"scope": "Species-specific",
"note": "",
"id": "silverleaf-nightshade-2"
},
{
"label": "Dogs & cats",
"sources": [
"U-silverleaf"
],
"scope": "Precautionary inference; pet evidence unresolved",
"note": "",
"id": "silverleaf-nightshade-3"
},
{
"label": "Other animals",
"sources": [
"U-silverleaf"
],
"scope": "Species-specific",
"note": "",
"id": "silverleaf-nightshade-4"
},
{
"label": "Plants & habitat",
"sources": [
"U-silverleaf",
"C-floristic-2020"
],
"scope": "Species-specific",
"note": "",
"id": "silverleaf-nightshade-5"
},
{
"label": "Management & timing",
"sources": [
"U-silverleaf"
],
"scope": "Management inference from root persistence",
"note": "",
"id": "silverleaf-nightshade-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"silverleaf-nightshade-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"silverleaf-nightshade-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 80; Solanum elaeagnifolium",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Solanum elaeagnifolium"
},
"source": "content/plants/silverleaf-nightshade.md"
}
---
# Silverleaf nightshade
*Solanum elaeagnifolium*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Toxic leaves and berries; persistent spreading roots.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinct from buffalobur, horsenettle and black nightshade species. Native status does not imply harmlessness or prevent it being invasive outside its native range.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright silverleaf nightshade stem with gray-green leaves and purple flowers in a grassy field.
Photo: Sam Kieschnick; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/2074835); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/2479337/original.JPG). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flower** — Purple star-shaped silverleaf nightshade flowers with prominent yellow anthers, held against a hand.
Photo: Sam Kieschnick; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/2074835); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/2479336/original.JPG). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruit** — Round yellow-green silverleaf nightshade berries with darker green bands on a drying gray stem.
Photo: Chris Quirin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/144270910); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/247577597/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A perennial with silvery, hairy leaves, often prickly stems and showy violet flowers. Young root sprouts may look like seedlings but lack seed leaves. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/)
## People
Leaves and berries contain variable amounts of toxic glycoalkaloids. Do not eat this plant or use berry color as a safety test. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/)
## Dogs & cats
Keep pets from chewing this identified nightshade as a precaution. The reviewed source documents human and livestock toxicity, but does not establish pet-specific clinical effects or a safe amount. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/)
*Evidence scope: Precautionary inference; pet evidence unresolved.*
## Other animals
Leaves and berries can poison livestock. Consumption by wild birds or small mammals does not establish safety for domestic animals. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/)
## Plants & habitat
Deep roots and persistent growth can reduce pasture or crop production through competition for water and nutrients. CNHP treats the species as native in Colorado. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/) [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf)
## Management & timing
Distinguish seedlings from root sprouts and plan repeated monitoring of established patches. Seek local management advice for extensive infestations. [U-silverleaf](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/)
*Evidence scope: Management inference from root persistence.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **U-silverleaf** — [Silverleaf nightshade](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/), University of California Statewide Integrated Pest Management. Accessed 2026-09-07T02:26:10+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=silverleaf-nightshade) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 80; Solanum elaeagnifolium. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Distinct from buffalobur, horsenettle and black nightshade species. Native status does not imply harmlessness or prevent it being invasive outside its native range.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| silverleaf-nightshade-1 | Identification | Species-specific | U-silverleaf | No quantitative safe exposure established here. |
| silverleaf-nightshade-2 | People | Species-specific | U-silverleaf | No quantitative safe exposure established here. |
| silverleaf-nightshade-3 | Dogs & cats | Precautionary inference; pet evidence unresolved | U-silverleaf | No quantitative safe exposure established here. |
| silverleaf-nightshade-4 | Other animals | Species-specific | U-silverleaf | No quantitative safe exposure established here. |
| silverleaf-nightshade-5 | Plants & habitat | Species-specific | U-silverleaf, C-floristic-2020 | No quantitative safe exposure established here. |
| silverleaf-nightshade-6 | Management & timing | Management inference from root persistence | U-silverleaf | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/index.md
---
{
"id": "snow-in-summer",
"name": "Snow-in-summer",
"scientific": "Cerastium tomentosum",
"category": "xeriscape",
"status": "Introduced garden groundcover",
"status_sources": [
"S12",
"S11"
],
"warning": "Spreading habit · Safety gap",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S12",
"S11",
"S25"
],
"description": "Snow-in-summer: Spreading habit · Safety gap. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S12",
"S11"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "snow-in-summer-1"
},
{
"label": "Plants & habitat",
"sources": [
"S11",
"S12"
],
"scope": "Species-specific + garden judgment",
"note": "Neighbor-crowding advice is inferred from aggressive, mat-forming growth.",
"reviewed": "2026-09-06",
"id": "snow-in-summer-2"
},
{
"label": "People",
"sources": [
"S11",
"S12"
],
"scope": "Evidence gap",
"note": "These horticultural profiles were not treated as toxicology clearance.",
"reviewed": "2026-09-06",
"id": "snow-in-summer-3"
},
{
"label": "Dogs & cats",
"sources": [
"S11",
"S12",
"S25"
],
"scope": "Evidence gap",
"note": "No safety conclusion is inferred from omission from a toxic-plant list.",
"reviewed": "2026-09-06",
"id": "snow-in-summer-4"
},
{
"label": "Other animals",
"sources": [
"S12"
],
"scope": "Species-specific benefit; safety gap",
"note": "",
"reviewed": "2026-09-06",
"id": "snow-in-summer-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"snow-in-summer-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"snow-in-summer-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"snow-in-summer-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/snow-in-summer.md"
}
---
# Snow-in-summer
*Cerastium tomentosum*
**Introduced garden groundcover.** [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/) [S11](https://extension.colostate.edu/resource/ground-cover-plants/)
> **Spreading habit · Safety gap.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Several white flowers with deeply notched petals above gray-green foliage.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cerastium_tomentosum_2023-05-28_6525.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/8d/Cerastium_tomentosum_2023-05-28_6525.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering stem** — Entire slender flowering stem against the sky, with opposite narrow leaves and a few flowers near its top.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cerastium_tomentosum_sl5.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f6/Cerastium_tomentosum_sl5.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf and stem** — Source-assembled photographic plate showing narrow hairy leaves in opposite pairs on stems, with a 20 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cerastium_tomentosum_sl21.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/ee/Cerastium_tomentosum_sl21.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A low mat of woolly, pale foliage and white flowers. Originates in Italy; CSU lists it for hot, dry, sunny groundcover sites. [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/) [S11](https://extension.colostate.edu/resource/ground-cover-plants/)
## Plants & habitat
Spreads by underground runners and seed. CSU describes it as aggressive; garden judgment: keep it from overtaking smaller neighbors. [S11](https://extension.colostate.edu/resource/ground-cover-plants/) [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/)
## People
The sources used for this profile do not establish human ingestion safety. [S11](https://extension.colostate.edu/resource/ground-cover-plants/) [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/)
## Dogs & cats
No species-specific veterinary safety conclusion was established in this review. Do not interpret that gap as pet-safe. [S11](https://extension.colostate.edu/resource/ground-cover-plants/) [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/) [S25](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants)
## Other animals
Flowers attract bees. Safety for grazing animals is not established by the sources reviewed. [S12](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S12** — [Cerastium tomentosum](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/), NC State Extension · Plant Toolbox. Accessed 2026-09-07T00:23:54+00:00. Locator: Description; origin; Wildlife Value.
- **S11** — [Ground Cover Plants](https://extension.colostate.edu/resource/ground-cover-plants/), Colorado State University Extension. Accessed 2026-09-07T00:23:54+00:00. Locator: Table 1b: hot, dry, sunny exposures; Cerastium tomentosum.
- **S25** — [Toxic and Non-Toxic Plants](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants), ASPCA Poison Control. Accessed 2026-09-07T00:23:56+00:00. Locator: Any plant material may cause vomiting or gastrointestinal upset; database limitations.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=snow-in-summer) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| snow-in-summer-1 | Recognize | Species-specific | S12, S11 | No quantitative exposure threshold established here. |
| snow-in-summer-2 | Plants & habitat | Species-specific + garden judgment | S11, S12 | Neighbor-crowding advice is inferred from aggressive, mat-forming growth. |
| snow-in-summer-3 | People | Evidence gap | S11, S12 | These horticultural profiles were not treated as toxicology clearance. |
| snow-in-summer-4 | Dogs & cats | Evidence gap | S11, S12, S25 | No safety conclusion is inferred from omission from a toxic-plant list. |
| snow-in-summer-5 | Other animals | Species-specific benefit; safety gap | S12 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md
---
{
"id": "snow-on-the-mountain",
"name": "Snow-on-the-mountain",
"scientific": "Euphorbia marginata",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Latex can damage skin and eyes; toxic if eaten",
"warning_tone": "danger",
"aliases": [
"snow on the mountain",
"variegated spurge"
],
"taxonomy_note": "The same common name is used for Aegopodium podagraria, an unrelated groundcover. This profile and its sap warnings apply to Euphorbia marginata.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-euphorbia-marginata",
"S27"
],
"description": "Snow-on-the-mountain: Latex can damage skin and eyes; toxic if eaten. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-euphorbia-marginata"
],
"scope": "Species-specific",
"note": "",
"id": "snow-on-the-mountain-1"
},
{
"label": "People",
"sources": [
"N-euphorbia-marginata"
],
"scope": "Species-specific",
"note": "",
"id": "snow-on-the-mountain-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-euphorbia-marginata"
],
"scope": "Species-specific",
"note": "",
"id": "snow-on-the-mountain-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "snow-on-the-mountain-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-euphorbia-marginata"
],
"scope": "Species-specific",
"note": "",
"id": "snow-on-the-mountain-5"
},
{
"label": "Management & timing",
"sources": [
"N-euphorbia-marginata"
],
"scope": "Management synthesis",
"note": "",
"id": "snow-on-the-mountain-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"snow-on-the-mountain-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 54; Euphorbia marginata",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Euphorbia marginata"
},
"source": "content/plants/snow-on-the-mountain.md"
}
---
# Snow-on-the-mountain
*Euphorbia marginata*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Latex can damage skin and eyes; toxic if eaten.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The same common name is used for Aegopodium podagraria, an unrelated groundcover. This profile and its sap warnings apply to Euphorbia marginata.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Tall, branching snow-on-the-mountain plant with green lower leaves and white-edged upper foliage.
Photo: Mark G; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/178461969); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/310545934/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers-bracts** — Top view of snow-on-the-mountain flower clusters surrounded by white-edged bracts against a dark background.
Photo: Michelle W. （鍾偉瑋）; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/94193832); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/156228977/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**upper-foliage** — Snow-on-the-mountain branch held in a hand, showing white leaf margins and small central flower structures.
Photo: Mark G; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/178461969); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/310545915/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An upright annual whose upper leaves develop striking white margins. Tiny flowers sit within the showy pale bracts. Damaged tissues exude milky latex. [N-euphorbia-marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/)
## People
Sap can cause dermatitis, mouth blistering and serious eye damage. Wear gloves and prevent sap contact, especially with eyes. [N-euphorbia-marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/)
## Dogs & cats
NC State flags this species as hazardous to pets. Prevent chewing and contact with latex; the source provides no safe pet exposure amount. [N-euphorbia-marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/)
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
A native plains annual also grown as an ornamental. It tolerates dry, poor soil and can reseed into unwanted patches. [N-euphorbia-marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/)
## Management & timing
Handle with protection and remove unwanted plants before seed maturation. Keep freshly cut material inaccessible to children and animals. [N-euphorbia-marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-euphorbia-marginata** — [Euphorbia marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/), NC State Extension. Accessed 2026-09-07T02:23:13+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=snow-on-the-mountain) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 54; Euphorbia marginata. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The same common name is used for Aegopodium podagraria, an unrelated groundcover. This profile and its sap warnings apply to Euphorbia marginata.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| snow-on-the-mountain-1 | Identification | Species-specific | N-euphorbia-marginata | No quantitative safe exposure established here. |
| snow-on-the-mountain-2 | People | Species-specific | N-euphorbia-marginata | No quantitative safe exposure established here. |
| snow-on-the-mountain-3 | Dogs & cats | Species-specific | N-euphorbia-marginata | No quantitative safe exposure established here. |
| snow-on-the-mountain-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| snow-on-the-mountain-5 | Plants & habitat | Species-specific | N-euphorbia-marginata | No quantitative safe exposure established here. |
| snow-on-the-mountain-6 | Management & timing | Management synthesis | N-euphorbia-marginata | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/index.md
---
{
"id": "soapweed-yucca",
"name": "Soapweed yucca",
"scientific": "Yucca glauca",
"category": "xeriscape",
"status": "Great Plains native",
"status_sources": [
"S09"
],
"warning": "Sharp leaves · Toxic to pets",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S09",
"S10"
],
"description": "Soapweed yucca: Sharp leaves · Toxic to pets. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S09"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "soapweed-yucca-1"
},
{
"label": "Plants & habitat",
"sources": [
"S09"
],
"scope": "Species-specific + garden judgment",
"note": "Placement advice is an inference from offsets and needle-sharp leaves.",
"reviewed": "2026-09-06",
"id": "soapweed-yucca-2"
},
{
"label": "People",
"sources": [
"S09"
],
"scope": "Species-specific physical feature; risk inference",
"note": "",
"reviewed": "2026-09-06",
"id": "soapweed-yucca-3"
},
{
"label": "Dogs & cats",
"sources": [
"S10"
],
"scope": "Genus-level",
"note": "",
"reviewed": "2026-09-06",
"id": "soapweed-yucca-4"
},
{
"label": "Other animals",
"sources": [
"S10",
"S09"
],
"scope": "Genus-level toxicity; species-specific benefit",
"note": "",
"reviewed": "2026-09-06",
"id": "soapweed-yucca-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/soapweed-yucca.md"
}
---
# Soapweed yucca
*Yucca glauca*
**Great Plains native.** [S09](https://plants.ces.ncsu.edu/plants/yucca-glauca/)
> **Sharp leaves · Toxic to pets.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Vertical stalk with pendulous cream-colored bell-shaped flowers and unopened buds.
Photo: Alvesgaspar; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Yucca_glauca_May_2014-2b.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/58/Yucca_glauca_May_2014-2b.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and fruit** — Broad clump of narrow, stiff leaves with upright stems carrying green capsules.
Photo: DouglasGoldman; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Yucca_glauca_OgallalaNE.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/13/Yucca_glauca_OgallalaNE.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**bud** — Close view of several elongated reddish-green flower buds on a yucca inflorescence.
Photo: Cephas; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Yucca_glauca_JRVdH_03.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/7b/Yucca_glauca_JRVdH_03.jpg). Source-supported identification with visual consistency check Photo selection verifies source labeling and visible consistency; it is not an independent specimen determination. Downloaded source thumbnail; no further pixel edits. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A rosette of narrow, pointed leaves with upright stalks of pale, downward-facing flowers. Suited to dry, rocky soil. [S09](https://plants.ces.ncsu.edu/plants/yucca-glauca/)
## Plants & habitat
Can expand through offsets and rhizomes. Garden judgment: allow room for the colony and sharp foliage. [S09](https://plants.ces.ncsu.edu/plants/yucca-glauca/)
## People
Needle-sharp leaf tips are a physical hazard. Human ingestion safety is not assessed here. [S09](https://plants.ces.ncsu.edu/plants/yucca-glauca/)
*Evidence scope: Species-specific physical feature; risk inference.*
## Dogs & cats
ASPCA lists Yucca species as toxic; vomiting is a reported sign. The evidence is for the genus, not an individual cultivar. [S10](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yucca)
*Evidence scope: Genus-level.*
## Other animals
ASPCA reports liver disease and dermatitis in horses exposed to yucca. Yucca glauca also supports yucca moths and wildlife habitat. [S10](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yucca) [S09](https://plants.ces.ncsu.edu/plants/yucca-glauca/)
*Evidence scope: Genus-level toxicity; species-specific benefit.*
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S09** — [Yucca glauca](https://plants.ces.ncsu.edu/plants/yucca-glauca/), NC State Extension · Plant Toolbox. Accessed 2026-09-07T00:23:53+00:00. Locator: Description; needle-sharp leaf points; wildlife relationships.
- **S10** — [Yucca](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yucca), ASPCA Poison Control. Accessed 2026-09-07T00:23:53+00:00. Locator: Scientific Name; Toxicity; Clinical Signs.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=soapweed-yucca) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| soapweed-yucca-1 | Recognize | Species-specific | S09 | No quantitative exposure threshold established here. |
| soapweed-yucca-2 | Plants & habitat | Species-specific + garden judgment | S09 | Placement advice is an inference from offsets and needle-sharp leaves. |
| soapweed-yucca-3 | People | Species-specific physical feature; risk inference | S09 | No quantitative exposure threshold established here. |
| soapweed-yucca-4 | Dogs & cats | Genus-level | S10 | No quantitative exposure threshold established here. |
| soapweed-yucca-5 | Other animals | Genus-level toxicity; species-specific benefit | S10, S09 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/index.md
---
{
"id": "spotted-knapweed",
"name": "Spotted knapweed",
"scientific": "Centaurea stoebe",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-spotted-knapweed"
],
"warning": "Competes with native vegetation",
"warning_tone": "caution",
"aliases": [
"Centaurea maculosa"
],
"taxonomy_note": "Some Colorado references use Centaurea maculosa for spotted knapweed. We retain their name in the citation record and use C. stoebe as the catalog label.",
"source_ids": [
"J-spotted-knapweed",
"C-descriptions",
"Fremont-list-definitions"
],
"description": "Spotted knapweed: Competes with native vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-spotted-knapweed"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-knapweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "This review did not establish a species-specific human toxicity profile.",
"id": "spotted-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "spotted-knapweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "Do not transfer Russian-knapweed horse toxicity to spotted knapweed without species-specific evidence.",
"id": "spotted-knapweed-5"
},
{
"id": "spotted-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"spotted-knapweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"spotted-knapweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"spotted-knapweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/spotted-knapweed.md"
}
---
# Spotted knapweed
*Centaurea stoebe*
**Colorado noxious weed · List B — Stop the spread.** [J-spotted-knapweed](https://www.jeffco.us/2181/Spotted-Knapweed)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Competes with native vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Some Colorado references use Centaurea maculosa for spotted knapweed. We retain their name in the citation record and use C. stoebe as the catalog label.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Close view of the purple tubular florets forming a knapweed flower head.
Photo: Alan Vernon; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Spotted_Knapweed_(Centaurea_maculosa).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/45/Spotted_Knapweed_%28Centaurea_maculosa%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Spotted knapweed is a species complex; North American invasive plants are often treated as C. stoebe subsp. micranthos. Some source photos retain the historically applied name Centaurea maculosa. Photographs do not establish subspecies or ploidy. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Branched slender stems with divided narrow leaves and scattered purple flower heads.
Photo: Agnieszka Kwiecień, Nova; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_stoebe_Chaber_nadre%C5%84ski_2020-07-12_02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b5/Centaurea_stoebe_Chaber_nadre%C5%84ski_2020-07-12_02.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Spotted knapweed is a species complex; North American invasive plants are often treated as C. stoebe subsp. micranthos. Some source photos retain the historically applied name Centaurea maculosa. Photographs do not establish subspecies or ploidy. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**involucral-bracts** — Flower-head base showing overlapping bracts with dark fringed tips, beside an unopened head.
Photo: Kristian Peters -- Fabelfroh 08:50, 2 November 2006 (UTC); [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Centaurea_stoebe_huellblaetter.jpeg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/21/Centaurea_stoebe_huellblaetter.jpeg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Spotted knapweed is a species complex; North American invasive plants are often treated as C. stoebe subsp. micranthos. Some source photos retain the historically applied name Centaurea maculosa. Photographs do not establish subspecies or ploidy. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Purple flowerheads with dark-tipped, fringed bracts; a short-lived perennial spreading mainly by seed. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Plants & habitat
An introduced noxious weed. Preventing seed production and maintaining desirable vegetation are parts of long-term control. [J-spotted-knapweed](https://www.jeffco.us/2181/Spotted-Knapweed)
## People
This review did not establish a species-specific human toxicity profile. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Do not transfer Russian-knapweed horse toxicity to spotted knapweed without species-specific evidence. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-spotted-knapweed** — [Spotted Knapweed](https://www.jeffco.us/2181/Spotted-Knapweed), Jefferson County, Colorado. Accessed 2026-09-07T00:27:26+00:00. Locator: Description, impacts, Colorado list designation, management.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=spotted-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Some Colorado references use Centaurea maculosa for spotted knapweed. We retain their name in the citation record and use C. stoebe as the catalog label.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| spotted-knapweed-1 | Recognize | Species-specific | C-descriptions | No quantitative exposure threshold established here. |
| spotted-knapweed-2 | Plants & habitat | Species-specific | J-spotted-knapweed | No quantitative exposure threshold established here. |
| spotted-knapweed-3 | People | Review limitation | Review limitation | This review did not establish a species-specific human toxicity profile. |
| spotted-knapweed-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| spotted-knapweed-5 | Other animals | Review limitation | Review limitation | Do not transfer Russian-knapweed horse toxicity to spotted knapweed without species-specific evidence. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md
---
{
"id": "spotted-spurge",
"name": "Spotted spurge",
"scientific": "Euphorbia maculata",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Milky sap can injure skin and eyes; keep pets from chewing",
"warning_tone": "caution",
"aliases": [
"Chamaesyce maculata",
"spotted sandmat",
"prostrate spurge"
],
"taxonomy_note": "CNHP treats Chamaesyce maculata as native, while documenting disagreement among earlier floras. NC State places it in Euphorbia. The common name prostrate spurge also applies to Euphorbia prostrata.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-euphorbia-maculata",
"S27"
],
"description": "Spotted spurge: Milky sap can injure skin and eyes; keep pets from chewing. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-euphorbia-maculata"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-spurge-1"
},
{
"label": "People",
"sources": [
"N-euphorbia-maculata"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-spurge-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-euphorbia-maculata"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-spurge-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "spotted-spurge-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-euphorbia-maculata"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-spurge-5"
},
{
"label": "Management & timing",
"sources": [
"N-euphorbia-maculata"
],
"scope": "Species-specific",
"note": "",
"id": "spotted-spurge-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"spotted-spurge-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"spotted-spurge-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 44; Chamaesyce maculata",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Chamaesyce maculata"
},
"source": "content/plants/spotted-spurge.md"
}
---
# Spotted spurge
*Euphorbia maculata*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Milky sap can injure skin and eyes; keep pets from chewing.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** CNHP treats Chamaesyce maculata as native, while documenting disagreement among earlier floras. NC State places it in Euphorbia. The common name prostrate spurge also applies to Euphorbia prostrata.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Low radiating reddish stems and small opposite leaves form a mat on stony ground.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_maculata_sl3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/67/Euphorbia_maculata_sl3.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Chamaesyce maculata is a synonym used for this taxon. Other small prostrate spurges can look similar; dark leaf spots alone are not diagnostic, and capsule hairs and seed characters may be needed for an unknown plant. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-stem** — Opposite oval leaves with dark central marks on reddish stems, photographed with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_maculata_sl5.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2f/Euphorbia_maculata_sl5.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Chamaesyce maculata is a synonym used for this taxon. Other small prostrate spurges can look similar; dark leaf spots alone are not diagnostic, and capsule hairs and seed characters may be needed for an unknown plant. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**capsules-seeds** — Opened green capsules and separate small reddish-brown seeds photographed with a 3 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Euphorbia_maculata_sl19.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/92/Euphorbia_maculata_sl19.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Chamaesyce maculata is a synonym used for this taxon. Other small prostrate spurges can look similar; dark leaf spots alone are not diagnostic, and capsule hairs and seed characters may be needed for an unknown plant. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A low annual mat with opposite, often purple-spotted leaves and hairy stems. Very small plants can already flower and set seed. Injured stems release white latex; do not break plants with bare hands to test this. [N-euphorbia-maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/)
## People
Latex can cause dermatitis and eye injury; ingestion can irritate or blister the mouth. Wear gloves and avoid sap contact, especially with eyes. [N-euphorbia-maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/)
## Dogs & cats
NC State identifies this species as a pet hazard. Keep animals from chewing or contacting freshly damaged plants; a safe exposure amount is not established. [N-euphorbia-maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/)
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
It rapidly reseeds disturbed beds, cracks and thin lawns. Native status does not prevent it becoming troublesome in a garden. [N-euphorbia-maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/)
## Management & timing
Remove plants early with gloves. Low growth escapes mowing, and even small seedlings may produce seed. [N-euphorbia-maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-euphorbia-maculata** — [Euphorbia maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=spotted-spurge) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 44; Chamaesyce maculata. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
CNHP treats Chamaesyce maculata as native, while documenting disagreement among earlier floras. NC State places it in Euphorbia. The common name prostrate spurge also applies to Euphorbia prostrata.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| spotted-spurge-1 | Identification | Species-specific | N-euphorbia-maculata | No quantitative safe exposure established here. |
| spotted-spurge-2 | People | Species-specific | N-euphorbia-maculata | No quantitative safe exposure established here. |
| spotted-spurge-3 | Dogs & cats | Species-specific | N-euphorbia-maculata | No quantitative safe exposure established here. |
| spotted-spurge-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| spotted-spurge-5 | Plants & habitat | Species-specific | N-euphorbia-maculata | No quantitative safe exposure established here. |
| spotted-spurge-6 | Management & timing | Species-specific | N-euphorbia-maculata | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/index.md
---
{
"id": "squarrose-knapweed",
"name": "Squarrose knapweed",
"scientific": "Centaurea virgata",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Spiny seedheads; loss of rangeland forage",
"warning_tone": "caution",
"aliases": [
"Centaurea squarrosa",
"Centaurea virgata subsp. squarrosa"
],
"taxonomy_note": "The state listing uses C. virgata. The NPS account and photographs concern the narrower taxon C. virgata subsp. squarrosa. Do not transfer Russian-knapweed horse toxicity to this species.",
"source_ids": [
"CO-rules-2025",
"NPS-squarrose",
"S27",
"Fremont-list-definitions"
],
"description": "Squarrose knapweed: Spiny seedheads; loss of rangeland forage. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"NPS-squarrose"
],
"scope": "Species-specific",
"note": "",
"id": "squarrose-knapweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"NPS-squarrose"
],
"scope": "Species-specific",
"note": "",
"id": "squarrose-knapweed-2"
},
{
"label": "People",
"sources": [
"NPS-squarrose"
],
"scope": "Physical-risk inference",
"note": "",
"id": "squarrose-knapweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"NPS-squarrose"
],
"scope": "Attachment and physical-risk inference",
"note": "",
"id": "squarrose-knapweed-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "squarrose-knapweed-5"
},
{
"id": "squarrose-knapweed-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"squarrose-knapweed-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"squarrose-knapweed-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/squarrose-knapweed.md"
}
---
# Squarrose knapweed
*Centaurea virgata*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spiny seedheads; loss of rangeland forage.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The state listing uses C. virgata. The NPS account and photographs concern the narrower taxon C. virgata subsp. squarrosa. Do not transfer Russian-knapweed horse toxicity to this species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower and head** — A small pink-purple flower head and slender leafy stem held in front of a hand.
Photo: Alexander Dubynin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/238399194); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/424414396/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observations are identified more narrowly as Centaurea virgata squarrosa. The source subspecies name is preserved. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**dry heads** — A slender branching stalk with dry flower heads held for viewing.
Photo: Alexander Dubynin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/274426317); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/493336493/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observations are identified more narrowly as Centaurea virgata squarrosa. The source subspecies name is preserved. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A low, spreading, finely branched plant with narrow divided foliage in dry rocky ground.
Photo: Alexander Dubynin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/274426317); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/493336428/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. The selected observations are identified more narrowly as Centaurea virgata squarrosa. The source subspecies name is preserved. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A branching perennial with a woody base, pink-purple heads and backward-curved spines on the flowerhead bracts. [NPS-squarrose](https://www.nps.gov/articles/squarrose-knapweed.htm)
## Plants & habitat
Dense stands reduce forage. Seed-bearing heads catch on animal hair, wool and clothing, spreading infestations. [NPS-squarrose](https://www.nps.gov/articles/squarrose-knapweed.htm)
## People
Hooked bract spines warrant gloves and careful handling. [NPS-squarrose](https://www.nps.gov/articles/squarrose-knapweed.htm)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Hooked heads can catch in fur; inspect animals after contact. Pet ingestion effects are not established in this review. [NPS-squarrose](https://www.nps.gov/articles/squarrose-knapweed.htm)
*Evidence scope: Attachment and physical-risk inference.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **NPS-squarrose** — [Exotic Species: Squarrose Knapweed](https://www.nps.gov/articles/squarrose-knapweed.htm), US National Park Service. Accessed 2026-09-07T01:18:57+00:00. Locator: Species or hybrid identity, description and ecology.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=squarrose-knapweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The state listing uses C. virgata. The NPS account and photographs concern the narrower taxon C. virgata subsp. squarrosa. Do not transfer Russian-knapweed horse toxicity to this species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| squarrose-knapweed-1 | Recognize | Species-specific | NPS-squarrose | No quantitative safe exposure established here. |
| squarrose-knapweed-2 | Plants & habitat | Species-specific | NPS-squarrose | No quantitative safe exposure established here. |
| squarrose-knapweed-3 | People | Physical-risk inference | NPS-squarrose | No quantitative safe exposure established here. |
| squarrose-knapweed-4 | Dogs & cats | Attachment and physical-risk inference | NPS-squarrose | No quantitative safe exposure established here. |
| squarrose-knapweed-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md
---
{
"id": "stinging-nettle",
"name": "Stinging nettle",
"scientific": "Urtica dioica",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Stinging hairs; this profile covers a taxonomic complex",
"warning_tone": "caution",
"aliases": [
"Urtica gracilis",
"Urtica dioica subsp. gracilis",
"American stinging nettle"
],
"taxonomy_note": "A broad, historical Urtica dioica treatment includes native American nettles (often now called Urtica gracilis) and introduced relatives. Colorado’s native status applies to the native elements; photos preserve their original identifications and do not prove every pictured subspecies occurs at your site.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-urtica-dioica",
"F-urtica",
"S27"
],
"description": "Stinging nettle: Stinging hairs; this profile covers a taxonomic complex. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-urtica-dioica",
"F-urtica"
],
"scope": "Broad Urtica dioica complex",
"note": "",
"id": "stinging-nettle-1"
},
{
"label": "People",
"sources": [
"N-urtica-dioica"
],
"scope": "Broad Urtica dioica complex",
"note": "",
"id": "stinging-nettle-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-urtica-dioica"
],
"scope": "Precautionary inference; pet evidence unresolved",
"note": "",
"id": "stinging-nettle-3"
},
{
"label": "Other animals",
"sources": [
"F-urtica"
],
"scope": "Broad-complex forage evidence",
"note": "",
"id": "stinging-nettle-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-urtica",
"N-urtica-dioica"
],
"scope": "Broad Urtica dioica complex",
"note": "",
"id": "stinging-nettle-5"
},
{
"label": "Management & timing",
"sources": [
"F-urtica"
],
"scope": "Broad-complex management",
"note": "",
"id": "stinging-nettle-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"stinging-nettle-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"stinging-nettle-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 84; Urtica dioica",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Urtica dioica"
},
"source": "content/plants/stinging-nettle.md"
}
---
# Stinging nettle
*Urtica dioica*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Stinging hairs; this profile covers a taxonomic complex.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** A broad, historical Urtica dioica treatment includes native American nettles (often now called Urtica gracilis) and introduced relatives. Colorado’s native status applies to the native elements; photos preserve their original identifications and do not prove every pictured subspecies occurs at your site.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering habit** — An upright nettle stem bearing toothed opposite leaves and slender branching flower clusters.
Photo: Przykuta; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Urtica_dioica_pokr%C3%B3j2_23.06.2012_p.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/84/Urtica_dioica_pokr%C3%B3j2_23.06.2012_p.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. This guide uses the explicitly requested broad Urtica dioica treatment. Photo 10-01 is source-labelled Urtica dioica. Photos 10-02 and 10-03 are source-labelled Urtica gracilis gracilis (subspecies rank), a native North American nettle also treated historically as Urtica dioica subsp. gracilis. Those narrow source identifications are preserved and are not asserted to be Eurasian U. dioica sensu stricto. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**native nettle foliage** — A long leafy branch with sharply toothed leaves and small hanging reproductive clusters; the source identifies Urtica gracilis gracilis.
Photo: John A Haskins; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/175285117); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/304622103/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. This guide uses the explicitly requested broad Urtica dioica treatment. Photo 10-01 is source-labelled Urtica dioica. Photos 10-02 and 10-03 are source-labelled Urtica gracilis gracilis (subspecies rank), a native North American nettle also treated historically as Urtica dioica subsp. gracilis. Those narrow source identifications are preserved and are not asserted to be Eurasian U. dioica sensu stricto. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**native nettle reproductive cluster** — A detached compact reproductive cluster photographed on a pale surface; the source identifies Urtica gracilis gracilis.
Photo: John A Haskins; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/175285117); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/304614058/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. This guide uses the explicitly requested broad Urtica dioica treatment. Photo 10-01 is source-labelled Urtica dioica. Photos 10-02 and 10-03 are source-labelled Urtica gracilis gracilis (subspecies rank), a native North American nettle also treated historically as Urtica dioica subsp. gracilis. Those narrow source identifications are preserved and are not asserted to be Eurasian U. dioica sensu stricto. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A rhizomatous perennial with opposite, toothed leaves, small greenish flower clusters and stinging hairs. It often forms dense patches in moist, fertile ground. [N-urtica-dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/) [F-urtica](https://research.fs.usda.gov/feis/species-reviews/urtdio)
*Evidence scope: Broad Urtica dioica complex.*
## People
Contact with stinging hairs can cause burning and itching. Avoid testing identification by touching the plant. [N-urtica-dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/)
*Evidence scope: Broad Urtica dioica complex.*
## Dogs & cats
Keep faces and exposed skin away from stinging vegetation. This is a contact precaution based on the plant’s hairs; the reviewed sources do not establish pet-specific ingestion effects or a safe exposure. [N-urtica-dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/)
*Evidence scope: Precautionary inference; pet evidence unresolved.*
## Other animals
Fresh nettles are generally unpalatable to livestock. Reports of processed nettle forage do not establish that standing plants or home preparations are safe for every animal. [F-urtica](https://research.fs.usda.gov/feis/species-reviews/urtdio)
*Evidence scope: Broad-complex forage evidence.*
## Plants & habitat
Patches can crowd a small garden yet provide cover and support insects in suitable habitat. Soil disturbance can redistribute rhizomes. [F-urtica](https://research.fs.usda.gov/feis/species-reviews/urtdio) [N-urtica-dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/)
*Evidence scope: Broad Urtica dioica complex.*
## Management & timing
Where removal is necessary, protect against contact and plan follow-up for rhizome regrowth. Mowing can produce new shoots rather than eliminate the patch. [F-urtica](https://research.fs.usda.gov/feis/species-reviews/urtdio)
*Evidence scope: Broad-complex management.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-urtica-dioica** — [Urtica dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/), NC State Extension. Accessed 2026-09-07T02:23:13+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **F-urtica** — [Stinging nettle](https://research.fs.usda.gov/feis/species-reviews/urtdio), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:50+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=stinging-nettle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 84; Urtica dioica. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
A broad, historical Urtica dioica treatment includes native American nettles (often now called Urtica gracilis) and introduced relatives. Colorado’s native status applies to the native elements; photos preserve their original identifications and do not prove every pictured subspecies occurs at your site.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| stinging-nettle-1 | Identification | Broad Urtica dioica complex | N-urtica-dioica, F-urtica | No quantitative safe exposure established here. |
| stinging-nettle-2 | People | Broad Urtica dioica complex | N-urtica-dioica | No quantitative safe exposure established here. |
| stinging-nettle-3 | Dogs & cats | Precautionary inference; pet evidence unresolved | N-urtica-dioica | No quantitative safe exposure established here. |
| stinging-nettle-4 | Other animals | Broad-complex forage evidence | F-urtica | No quantitative safe exposure established here. |
| stinging-nettle-5 | Plants & habitat | Broad Urtica dioica complex | F-urtica, N-urtica-dioica | No quantitative safe exposure established here. |
| stinging-nettle-6 | Management & timing | Broad-complex management | F-urtica | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/index.md
---
{
"id": "sulfur-cinquefoil",
"name": "Sulfur cinquefoil",
"scientific": "Potentilla recta",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Persistent pasture and roadside weed",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Colorado has native cinquefoils. Confirm Potentilla recta before removing a yellow-flowered cinquefoil.",
"source_ids": [
"CO-rules-2025",
"N-potentilla-recta",
"S27",
"Fremont-list-definitions"
],
"description": "Sulfur cinquefoil: Persistent pasture and roadside weed. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-potentilla-recta"
],
"scope": "Species-specific",
"note": "",
"id": "sulfur-cinquefoil-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-potentilla-recta"
],
"scope": "Species-specific",
"note": "",
"id": "sulfur-cinquefoil-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "sulfur-cinquefoil-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "sulfur-cinquefoil-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "sulfur-cinquefoil-5"
},
{
"id": "sulfur-cinquefoil-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"sulfur-cinquefoil-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"sulfur-cinquefoil-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"sulfur-cinquefoil-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/sulfur-cinquefoil.md"
}
---
# Sulfur cinquefoil
*Potentilla recta*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Persistent pasture and roadside weed.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Colorado has native cinquefoils. Confirm Potentilla recta before removing a yellow-flowered cinquefoil.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — A pale yellow, five-petaled sulphur-cinquefoil flower showing its central stamens.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Potentilla_recta_(3727318142)_(cropped).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/70/Potentilla_recta_%283727318142%29_%28cropped%29.jpg). Source-identified photograph with visual consistency check the pale yellow petals, lack of well developed basal leaves, well developed stem leaves, and hirsute stems are characteristic of this species Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**stem and leaves** — A hairy upright sulphur-cinquefoil stem with palmate leaves viewed from the side.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Potentilla_recta_sl12.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/04/Potentilla_recta_sl12.jpg). Source-identified photograph with visual consistency check Stipe with leaves Taxonym: Potentilla recta ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: Schwarze Lacke, Vienna-Floridsdorf - ca. 160 m a.s.l. Habitat: dry meadows Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**seedlings** — Young sulphur-cinquefoil plants with rounded, lobed first leaves in a cultivation tray.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Potentilla_recta_15-p.bot-poten.recta-24.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f0/Potentilla_recta_15-p.bot-poten.recta-24.jpg). Source-identified photograph with visual consistency check Nom français : potentille dressée. Nom anglais : sulphur cinquefoil. Plantules de potentille dressée, vue de dessus (culture en caissette). Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A hairy perennial with pale yellow, five-petaled flowers and leaves divided into toothed leaflets. [N-potentilla-recta](https://plants.ces.ncsu.edu/plants/potentilla-recta/)
## Plants & habitat
Self-seeds in pastures, disturbed ground and roadsides. Persistent seeds require follow-up after removal. [N-potentilla-recta](https://plants.ces.ncsu.edu/plants/potentilla-recta/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-potentilla-recta** — [potentilla recta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/potentilla-recta/), NC State Extension. Accessed 2026-09-07T01:04:54+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=sulfur-cinquefoil) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Colorado has native cinquefoils. Confirm Potentilla recta before removing a yellow-flowered cinquefoil.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| sulfur-cinquefoil-1 | Recognize | Species-specific | N-potentilla-recta | No quantitative safe exposure established here. |
| sulfur-cinquefoil-2 | Plants & habitat | Species-specific | N-potentilla-recta | No quantitative safe exposure established here. |
| sulfur-cinquefoil-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| sulfur-cinquefoil-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| sulfur-cinquefoil-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md
---
{
"id": "tall-buttercup",
"name": "Tall buttercup",
"scientific": "Ranunculus acris",
"category": "invasive",
"status": "Introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Fresh plant irritation and animal poisoning hazard",
"warning_tone": "danger",
"aliases": [
"meadow buttercup",
"common buttercup"
],
"taxonomy_note": "The pet warning is genus-level evidence. It does not establish identical toxicity across every Ranunculus or justify blanket removal of native buttercups.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-ranunculus-acris",
"P-buttercup",
"S27"
],
"description": "Tall buttercup: Fresh plant irritation and animal poisoning hazard. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-ranunculus-acris"
],
"scope": "Species-specific",
"note": "",
"id": "tall-buttercup-1"
},
{
"label": "People",
"sources": [
"N-ranunculus-acris"
],
"scope": "Source-field limitation",
"note": "",
"id": "tall-buttercup-2"
},
{
"label": "Dogs & cats",
"sources": [
"P-buttercup"
],
"scope": "Genus-level veterinary evidence",
"note": "",
"id": "tall-buttercup-3"
},
{
"label": "Other animals",
"sources": [
"N-ranunculus-acris"
],
"scope": "Species-specific",
"note": "",
"id": "tall-buttercup-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-ranunculus-acris"
],
"scope": "Species-specific",
"note": "",
"id": "tall-buttercup-5"
},
{
"label": "Management & timing",
"sources": [
"N-ranunculus-acris",
"P-buttercup"
],
"scope": "Management synthesis",
"note": "",
"id": "tall-buttercup-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tall-buttercup-2"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 75; Ranunculus acris",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Ranunculus acris"
},
"source": "content/plants/tall-buttercup.md"
}
---
# Tall buttercup
*Ranunculus acris*
**Introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Fresh plant irritation and animal poisoning hazard.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The pet warning is genus-level evidence. It does not establish identical toxicity across every Ranunculus or justify blanket removal of native buttercups.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit-flowers** — Meadow buttercup growing among grass, with yellow flowers held above deeply divided basal leaves.
Photo: Daniel Cahen; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/63990191); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/102792093/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves** — Deeply divided green basal leaves of meadow buttercup among surrounding grass.
Photo: Daniel Cahen; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/63990191); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/102792144/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**fruit** — Cluster of green developing meadow buttercup achenes at the top of a slender stalk.
Photo: Daniel Cahen; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/63990191); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/102792039/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An upright perennial of moist meadows and disturbed ground with glossy yellow flowers. Confirm the species: Colorado has many native buttercups as well. [N-ranunculus-acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/)
## People
NC State flags poisonous characteristics but presents livestock effects in its symptom field. Human exposure severity and a safe amount remain unresolved here. [N-ranunculus-acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/)
*Evidence scope: Source-field limitation.*
## Dogs & cats
ASPCA lists Ranunculus species as toxic to pets through an irritant toxin. Reported group-level signs include drooling, oral ulcers, vomiting, diarrhea and unsteady movement. [P-buttercup](https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/buttercup)
*Evidence scope: Genus-level veterinary evidence.*
## Other animals
NC State reports mouth injury, diarrhea and potentially severe systemic effects in livestock ingesting this species. [N-ranunculus-acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/)
## Plants & habitat
A nonnative perennial that grows in moist meadows, pastures and roadsides. Its flowers also attract pollinating insects. [N-ranunculus-acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/)
## Management & timing
Confirm identity and prevent animal access to suspect plants or contaminated forage. Choose control for the site rather than treating every yellow buttercup as this species. [N-ranunculus-acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/) [P-buttercup](https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/buttercup)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-ranunculus-acris** — [Ranunculus acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/), NC State Extension. Accessed 2026-09-07T02:23:13+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **P-buttercup** — [Buttercup](https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/buttercup), ASPCA Animal Poison Control. Accessed 2026-09-07T02:26:11+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tall-buttercup) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 75; Ranunculus acris. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The pet warning is genus-level evidence. It does not establish identical toxicity across every Ranunculus or justify blanket removal of native buttercups.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| tall-buttercup-1 | Identification | Species-specific | N-ranunculus-acris | No quantitative safe exposure established here. |
| tall-buttercup-2 | People | Source-field limitation | N-ranunculus-acris | No quantitative safe exposure established here. |
| tall-buttercup-3 | Dogs & cats | Genus-level veterinary evidence | P-buttercup | No quantitative safe exposure established here. |
| tall-buttercup-4 | Other animals | Species-specific | N-ranunculus-acris | No quantitative safe exposure established here. |
| tall-buttercup-5 | Plants & habitat | Species-specific | N-ranunculus-acris | No quantitative safe exposure established here. |
| tall-buttercup-6 | Management & timing | Management synthesis | N-ranunculus-acris, P-buttercup | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md
---
{
"id": "tall-larkspur",
"name": "Tall larkspur",
"scientific": "Delphinium barbeyi",
"category": "native",
"status": "Native Colorado wildflower; grazing and ingestion hazard",
"status_sources": [
"C-routt-guide"
],
"warning": "Serious livestock and pet poisoning hazard",
"warning_tone": "danger",
"aliases": [
"Barbey’s larkspur"
],
"taxonomy_note": "This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.",
"source_ids": [
"C-routt-guide",
"ARS-larkspur",
"A-larkspur",
"S27"
],
"description": "Tall larkspur: Serious livestock and pet poisoning hazard. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"ARS-larkspur"
],
"scope": "Larkspur-group morphology; use a species key",
"note": "",
"id": "tall-larkspur-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-routt-guide"
],
"scope": "Species-specific",
"note": "",
"id": "tall-larkspur-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tall-larkspur-3"
},
{
"label": "Dogs & cats",
"sources": [
"A-larkspur"
],
"scope": "Genus-level warning; no species-specific pet threshold",
"note": "",
"id": "tall-larkspur-4"
},
{
"label": "Other animals",
"sources": [
"ARS-larkspur"
],
"scope": "Larkspur-group evidence",
"note": "",
"id": "tall-larkspur-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tall-larkspur-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/tall-larkspur.md"
}
---
# Tall larkspur
*Delphinium barbeyi*
**Native Colorado wildflower; grazing and ingestion hazard.** [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
> **Serious livestock and pet poisoning hazard.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering stem** — A blue-flowered larkspur stem with several spurred flowers and divided stem leaves.
Photo: Ms. Sticky; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Delphinium_barbeyi.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/68/Delphinium_barbeyi.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and habitat** — Several tall purple-flowered stems rising above leafy subalpine vegetation, with a mountain slope behind.
Photo: John Powers; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/66494294); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/107202729/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Side view of deep purple flowers showing elongated backward-pointing spurs and fine hairs.
Photo: John Powers; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/66494294); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/107202638/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Tall larkspurs bear clusters of blue spurred flowers above deeply lobed leaves. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)
*Evidence scope: Larkspur-group morphology; use a species key.*
## Plants & habitat
Routt County records tall larkspur on higher-elevation slopes and in aspen habitats. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
ASPCA lists Delphinium species as toxic to dogs and cats. Alkaloids can disrupt nerve and muscle function; suspected ingestion needs prompt veterinary attention. [A-larkspur](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur)
*Evidence scope: Genus-level warning; no species-specific pet threshold.*
## Other animals
Larkspur is a major cattle-poisoning concern. All parts are toxic; severity varies with species, growth stage and conditions. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)
*Evidence scope: Larkspur-group evidence.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **ARS-larkspur** — [Larkspur (Delphinium spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/), USDA Agricultural Research Service. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **A-larkspur** — [Larkspur — Delphinium species](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur), ASPCA Poison Control. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tall-larkspur) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| tall-larkspur-1 | Recognize | Larkspur-group morphology; use a species key | ARS-larkspur | No quantitative safe exposure established here. |
| tall-larkspur-2 | Plants & habitat | Species-specific | C-routt-guide | No quantitative safe exposure established here. |
| tall-larkspur-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tall-larkspur-4 | Dogs & cats | Genus-level warning; no species-specific pet threshold | A-larkspur | No quantitative safe exposure established here. |
| tall-larkspur-5 | Other animals | Larkspur-group evidence | ARS-larkspur | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md
---
{
"id": "tamarisk",
"name": "Tamarisk",
"scientific": "Tamarix ramosissima",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-saltcedar---tamarisk"
],
"warning": "Alters riparian vegetation",
"warning_tone": "caution",
"aliases": [
"saltcedar",
"Tamarix chinensis"
],
"taxonomy_note": "The county covers T. chinensis and T. ramosissima together. Photos and broad saltcedar descriptions cannot reliably resolve every hybrid or species. No universal water-saving amount is inferred from removal.",
"source_ids": [
"J-saltcedar---tamarisk",
"Fremont-list-definitions"
],
"description": "Tamarisk: Alters riparian vegetation. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-saltcedar---tamarisk"
],
"scope": "Species-specific",
"note": "",
"id": "tamarisk-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-saltcedar---tamarisk"
],
"scope": "Species-group ecology; editorial management advice",
"note": "",
"id": "tamarisk-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human chemical-toxicity effects were not established in this review.",
"id": "tamarisk-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "tamarisk-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "This review does not establish unrestricted livestock feeding safety.",
"id": "tamarisk-5"
},
{
"id": "tamarisk-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tamarisk-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"tamarisk-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"tamarisk-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/tamarisk.md"
}
---
# Tamarisk
*Tamarix ramosissima*
**Colorado noxious weed · List B — Stop the spread.** [J-saltcedar---tamarisk](https://www.jeffco.us/2216/Saltcedar---Tamarisk)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Alters riparian vegetation.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The county covers T. chinensis and T. ramosissima together. Photos and broad saltcedar descriptions cannot reliably resolve every hybrid or species. No universal water-saving amount is inferred from removal.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Slender pink flower racemes on fine twiggy branches.
Photo: Jerzy Opioła; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Tamarix_ramosissima_a1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/72/Tamarix_ramosissima_a1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Saltcedars are difficult to separate by general photographs and hybridize, especially T. ramosissima with T. chinensis in North America. These photos are source-identified T. ramosissima references; species purity is not verified from photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering-branches** — Slender branching pink racemes spread across thin woody twigs; fine green branchlets are visible behind.
Photo: Jerzy Opioła; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Tamarix_ramosissima_a3.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/41/Tamarix_ramosissima_a3.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Saltcedars are difficult to separate by general photographs and hybridize, especially T. ramosissima with T. chinensis in North America. These photos are source-identified T. ramosissima references; species purity is not verified from photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Woody shrub or small tree with a branching crown covered in pink flower clusters.
Photo: Dr. Alexey Yakovlev; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Tamarix_ramosissima_(Tamaricaceae)_(53139152639).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/ce/Tamarix_ramosissima_%28Tamaricaceae%29_%2853139152639%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Saltcedars are difficult to separate by general photographs and hybridize, especially T. ramosissima with T. chinensis in North America. These photos are source-identified T. ramosissima references; species purity is not verified from photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A deciduous shrub or small tree with fine, scale-like leaves and narrow clusters of tiny pink to white flowers. [J-saltcedar---tamarisk](https://www.jeffco.us/2216/Saltcedar---Tamarisk)
## Plants & habitat
Introduced riparian plants that accumulate salt in foliage and can regrow from cut stems or roots. Restoration needs site-specific planning and follow-up. [J-saltcedar---tamarisk](https://www.jeffco.us/2216/Saltcedar---Tamarisk)
*Evidence scope: Species-group ecology; editorial management advice.*
## People
Human chemical-toxicity effects were not established in this review. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
This review does not establish unrestricted livestock feeding safety. This is an evidence gap, not proof of safety.
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-saltcedar---tamarisk** — [Saltcedar - Tamarisk](https://www.jeffco.us/2216/Saltcedar---Tamarisk), Jefferson County, Colorado. Accessed 2026-09-07T00:27:25+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tamarisk) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
The county covers T. chinensis and T. ramosissima together. Photos and broad saltcedar descriptions cannot reliably resolve every hybrid or species. No universal water-saving amount is inferred from removal.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| tamarisk-1 | Recognize | Species-specific | J-saltcedar---tamarisk | No quantitative exposure threshold established here. |
| tamarisk-2 | Plants & habitat | Species-group ecology; editorial management advice | J-saltcedar---tamarisk | No quantitative exposure threshold established here. |
| tamarisk-3 | People | Review limitation | Review limitation | Human chemical-toxicity effects were not established in this review. |
| tamarisk-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| tamarisk-5 | Other animals | Review limitation | Review limitation | This review does not establish unrestricted livestock feeding safety. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md
---
{
"id": "tansy-ragwort",
"name": "Tansy ragwort",
"scientific": "Jacobaea vulgaris",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Poisonous to livestock; harmful alkaloids",
"warning_tone": "danger",
"aliases": [
"Senecio jacobaea"
],
"taxonomy_note": "This is not common tansy or common groundsel. The attempted NC State Jacobaea URL returned a common-groundsel account and was excluded as mismatched evidence.",
"source_ids": [
"CO-rules-2025",
"WA-tansy-ragwort",
"S27",
"A-ragwort",
"Fremont-list-definitions"
],
"description": "Tansy ragwort: Poisonous to livestock; harmful alkaloids. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-tansy-ragwort"
],
"scope": "Species-specific",
"note": "",
"id": "tansy-ragwort-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-tansy-ragwort"
],
"scope": "Species-specific",
"note": "",
"id": "tansy-ragwort-2"
},
{
"label": "People",
"sources": [
"WA-tansy-ragwort"
],
"scope": "Species-specific",
"note": "",
"id": "tansy-ragwort-3"
},
{
"label": "Dogs & cats",
"sources": [
"A-ragwort",
"WA-tansy-ragwort"
],
"scope": "Historical genus-group warning; species-specific alkaloid evidence",
"note": "",
"id": "tansy-ragwort-4"
},
{
"label": "Other animals",
"sources": [
"WA-tansy-ragwort"
],
"scope": "Species-specific",
"note": "",
"id": "tansy-ragwort-5"
},
{
"id": "tansy-ragwort-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tansy-ragwort-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/tansy-ragwort.md"
}
---
# Tansy ragwort
*Jacobaea vulgaris*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Poisonous to livestock; harmful alkaloids.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This is not common tansy or common groundsel. The attempted NC State Jacobaea URL returned a common-groundsel account and was excluded as mismatched evidence.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering habit** — An upright flowering plant with yellow heads and deeply divided leaves.
Photo: jamie-aa; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/126244220); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/214180355/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower heads** — Close view of yellow ray florets and central disks on several heads.
Photo: jamie-aa; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/126244220); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/214200970/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**head underside** — The green undersides and bracts of flower heads viewed from below.
Photo: jamie-aa; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/126244220); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/214200978/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Ruffled, divided leaves and clusters of yellow daisy-like flowerheads, typically with about thirteen ray flowers. [WA-tansy-ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort)
## Plants & habitat
Seed and regrowth spread plants in disturbed fields and pastures. Mowing alone can produce repeated regrowth. [WA-tansy-ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort)
## People
All parts contain toxic alkaloids. Do not use the plant in food or home remedies; direct human exposure thresholds are not established here. [WA-tansy-ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort)
## Dogs & cats
ASPCA lists Senecio species as toxic to dogs and cats, with liver injury from pyrrolizidine alkaloids. Tansy ragwort was formerly Senecio jacobaea; the ASPCA warning is broader than this species and gives no pet-specific dose. [A-ragwort](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/ragwort) [WA-tansy-ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort)
*Evidence scope: Historical genus-group warning; species-specific alkaloid evidence.*
## Other animals
All parts are poisonous to livestock. Removed or wilted plants can be more palatable; keep cut material and contaminated forage away from animals. [WA-tansy-ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-tansy-ragwort** — [Tansy Ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:01+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
- **A-ragwort** — [Ragwort](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/ragwort), ASPCA Poison Control. Accessed 2026-09-07T01:16:20+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tansy-ragwort) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This is not common tansy or common groundsel. The attempted NC State Jacobaea URL returned a common-groundsel account and was excluded as mismatched evidence.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| tansy-ragwort-1 | Recognize | Species-specific | WA-tansy-ragwort | No quantitative safe exposure established here. |
| tansy-ragwort-2 | Plants & habitat | Species-specific | WA-tansy-ragwort | No quantitative safe exposure established here. |
| tansy-ragwort-3 | People | Species-specific | WA-tansy-ragwort | No quantitative safe exposure established here. |
| tansy-ragwort-4 | Dogs & cats | Historical genus-group warning; species-specific alkaloid evidence | A-ragwort, WA-tansy-ragwort | No quantitative safe exposure established here. |
| tansy-ragwort-5 | Other animals | Species-specific | WA-tansy-ragwort | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/index.md
---
{
"id": "taurian-thistle",
"name": "Taurian thistle",
"scientific": "Onopordum tauricum",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Sharp spines; taxon listed as Scotch thistle",
"warning_tone": "caution",
"aliases": [
"Scotch thistle",
"bull cottonthistle"
],
"taxonomy_note": "Onopordum acanthium has its own profile. Identification can be difficult; the reference study documents morphological variation among Italian populations, not Colorado impact severity.",
"source_ids": [
"CO-rules-2025",
"P-tauricum",
"S27",
"Fremont-list-definitions"
],
"description": "Taurian thistle: Sharp spines; taxon listed as Scotch thistle. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"P-tauricum"
],
"scope": "Species-specific",
"note": "",
"id": "taurian-thistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"CO-rules-2025"
],
"scope": "Regulatory status",
"note": "",
"id": "taurian-thistle-2"
},
{
"label": "People",
"sources": [
"P-tauricum"
],
"scope": "Physical-risk inference",
"note": "",
"id": "taurian-thistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"P-tauricum"
],
"scope": "Physical-risk inference",
"note": "",
"id": "taurian-thistle-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "taurian-thistle-5"
},
{
"id": "taurian-thistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"taurian-thistle-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/taurian-thistle.md"
}
---
# Taurian thistle
*Onopordum tauricum*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Sharp spines; taxon listed as Scotch thistle.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Onopordum acanthium has its own profile. Identification can be difficult; the reference study documents morphological variation among Italian populations, not Colorado impact severity.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower and bracts** — A purple Taurian-thistle head with long pointed bracts beneath it.
Photo: Louis Aureglia; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/219395202); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/388325973/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification and visible consistency checked; not an independent specimen determination. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf and stem** — Large, sharply lobed and spiny Taurian-thistle leaves attached to a strongly winged stem.
Photo: Louis Aureglia; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/219395202); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/388326013/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification and visible consistency checked; not an independent specimen determination. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Tall, branching Taurian thistles bearing numerous purple flower heads beside a roadside barrier.
Photo: Louis Aureglia; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/219395202); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/388326025/original.jpeg). Explicit research-grade community taxon identification; visually inspected Community identification and visible consistency checked; not an independent specimen determination. iNaturalist large-size rendering; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Tall, spiny, winged stems and glandular hairs; often greener and less woolly than O. acanthium. [P-tauricum](https://pmc.ncbi.nlm.nih.gov/articles/PMC10934427/)
## Plants & habitat
Colorado lists O. tauricum as a separate List B entry under the common name Scotch thistle. Confirm the species with your county program. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
*Evidence scope: Regulatory status.*
## People
Spiny stems and leaves warrant protective handling. [P-tauricum](https://pmc.ncbi.nlm.nih.gov/articles/PMC10934427/)
*Evidence scope: Physical-risk inference.*
## Dogs & cats
Spines may injure paws or mouths. No pet-specific chemical toxicity is established here. [P-tauricum](https://pmc.ncbi.nlm.nih.gov/articles/PMC10934427/)
*Evidence scope: Physical-risk inference.*
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **P-tauricum** — [Morphological and Genomic Differences in the Italian Populations of Onopordum tauricum](https://pmc.ncbi.nlm.nih.gov/articles/PMC10934427/), Plants journal / authors; archived by US National Library of Medicine. Accessed 2026-09-07T01:18:57+00:00. Locator: Species or hybrid identity, description and ecology.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=taurian-thistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Onopordum acanthium has its own profile. Identification can be difficult; the reference study documents morphological variation among Italian populations, not Colorado impact severity.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| taurian-thistle-1 | Recognize | Species-specific | P-tauricum | No quantitative safe exposure established here. |
| taurian-thistle-2 | Plants & habitat | Regulatory status | CO-rules-2025 | No quantitative safe exposure established here. |
| taurian-thistle-3 | People | Physical-risk inference | P-tauricum | No quantitative safe exposure established here. |
| taurian-thistle-4 | Dogs & cats | Physical-risk inference | P-tauricum | No quantitative safe exposure established here. |
| taurian-thistle-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md
---
{
"id": "tree-of-heaven",
"name": "Tree of heaven",
"scientific": "Ailanthus altissima",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Root suckers form persistent thickets",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Distinguish from sumacs and walnuts using leaflet bases and other features. Established root systems require a coordinated control plan.",
"source_ids": [
"CO-rules-2025",
"N-ailanthus-altissima",
"S27",
"Fremont-list-definitions"
],
"description": "Tree of heaven: Root suckers form persistent thickets. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-ailanthus-altissima"
],
"scope": "Species-specific",
"note": "",
"id": "tree-of-heaven-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-ailanthus-altissima"
],
"scope": "Species-specific",
"note": "",
"id": "tree-of-heaven-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tree-of-heaven-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tree-of-heaven-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tree-of-heaven-5"
},
{
"id": "tree-of-heaven-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tree-of-heaven-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"tree-of-heaven-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"tree-of-heaven-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/tree-of-heaven.md"
}
---
# Tree of heaven
*Ailanthus altissima*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Root suckers form persistent thickets.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinguish from sumacs and walnuts using leaflet bases and other features. Established root systems require a coordinated control plan.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Mature tree with a broad rounded leafy crown and single trunk.
Photo: Darkone; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:G%C3%B6tterbaum_(Ailanthus_altissima).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/eb/G%C3%B6tterbaum_%28Ailanthus_altissima%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**foliage** — Long pinnately compound leaves with many paired green leaflets.
Photo: Karduelis; [Public domain](https://commons.wikimedia.org/wiki/File:Ailanthus_altissima-1.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Ailanthus_altissima-1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/9a/Ailanthus_altissima-1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**samaras** — Four dry elongated winged fruits, each with a central seed, photographed with a scale.
Photo: Steve Hurst @ USDA-NRCS PLANTS Database; [Public domain](https://commons.wikimedia.org/wiki/File:Ailanthus_altissima_seeds.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Ailanthus_altissima_seeds.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c6/Ailanthus_altissima_seeds.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Large compound leaves have leaflets with glandular teeth near their bases; fruits are elongated, winged samaras. [N-ailanthus-altissima](https://plants.ces.ncsu.edu/plants/ailanthus-altissima/)
## Plants & habitat
Seeds and suckers form dense thickets that displace vegetation. It is a host for spotted lanternfly; tree presence does not prove that insect is locally present. [N-ailanthus-altissima](https://plants.ces.ncsu.edu/plants/ailanthus-altissima/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-ailanthus-altissima** — [ailanthus altissima — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ailanthus-altissima/), NC State Extension. Accessed 2026-09-07T01:04:55+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tree-of-heaven) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Distinguish from sumacs and walnuts using leaflet bases and other features. Established root systems require a coordinated control plan.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| tree-of-heaven-1 | Recognize | Species-specific | N-ailanthus-altissima | No quantitative safe exposure established here. |
| tree-of-heaven-2 | Plants & habitat | Species-specific | N-ailanthus-altissima | No quantitative safe exposure established here. |
| tree-of-heaven-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tree-of-heaven-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tree-of-heaven-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md
---
{
"id": "tumble-mustard",
"name": "Tumble mustard",
"scientific": "Sisymbrium altissimum",
"category": "invasive",
"status": "Introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Another tumbleweed: brittle plants scatter persistent seed",
"warning_tone": "caution",
"aliases": [
"tall tumblemustard",
"Jim Hill mustard",
"tall hedge mustard"
],
"taxonomy_note": "Tumbleweed describes a dispersal habit, not one species. This mustard is distinct from Russian thistle, kochia and the perennial baby’s-breath species.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-sisymbrium",
"S27"
],
"description": "Tumble mustard: Another tumbleweed: brittle plants scatter persistent seed. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-sisymbrium"
],
"scope": "Species-specific",
"note": "",
"id": "tumble-mustard-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tumble-mustard-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "tumble-mustard-3"
},
{
"label": "Other animals",
"sources": [
"F-sisymbrium"
],
"scope": "Species-specific",
"note": "",
"id": "tumble-mustard-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-sisymbrium"
],
"scope": "Species-specific",
"note": "",
"id": "tumble-mustard-5"
},
{
"label": "Management & timing",
"sources": [
"F-sisymbrium"
],
"scope": "Species-specific",
"note": "",
"id": "tumble-mustard-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"tumble-mustard-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"tumble-mustard-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"tumble-mustard-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 80; Sisymbrium altissimum",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Sisymbrium altissimum"
},
"source": "content/plants/tumble-mustard.md"
}
---
# Tumble mustard
*Sisymbrium altissimum*
**Introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Another tumbleweed: brittle plants scatter persistent seed.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Tumbleweed describes a dispersal habit, not one species. This mustard is distinct from Russian thistle, kochia and the perennial baby’s-breath species.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Tall, finely branched tumble mustard plant carrying many small yellow flowers.
Photo: Ben Keen; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/50507348); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/80198044/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**flowers** — Small pale-yellow, four-petaled tumble mustard flowers and green buds along slender stems.
Photo: Ben Keen; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/50507348); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/80198028/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaves-stem** — Narrow, deeply divided upper tumble mustard leaves and upright green stems held against a hand.
Photo: Sam Kieschnick; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/110389698); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/186212610/original.jpg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An introduced annual or biennial with a rounded, finely branching mature form and long narrow seedpods. Leaves become smaller toward the top. [F-sisymbrium](https://research.fs.usda.gov/feis/species-reviews/sisalt)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Livestock and wildlife consume some young growth. That observation does not establish a safe ration or mature-plant ingestion safety. [F-sisymbrium](https://research.fs.usda.gov/feis/species-reviews/sisalt)
## Plants & habitat
The dry stem can break at its base and move with the wind, releasing seed gradually. It colonizes disturbed ground and can be transported by machinery. [F-sisymbrium](https://research.fs.usda.gov/feis/species-reviews/sisalt)
## Management & timing
Prevent seed maturation, reduce unnecessary soil disturbance and maintain desired vegetation. Check equipment and field edges for transported plants. [F-sisymbrium](https://research.fs.usda.gov/feis/species-reviews/sisalt)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-sisymbrium** — [Tall tumblemustard](https://research.fs.usda.gov/feis/species-reviews/sisalt), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:49+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=tumble-mustard) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 80; Sisymbrium altissimum. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Tumbleweed describes a dispersal habit, not one species. This mustard is distinct from Russian thistle, kochia and the perennial baby’s-breath species.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| tumble-mustard-1 | Identification | Species-specific | F-sisymbrium | No quantitative safe exposure established here. |
| tumble-mustard-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tumble-mustard-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tumble-mustard-4 | Other animals | Species-specific | F-sisymbrium | No quantitative safe exposure established here. |
| tumble-mustard-5 | Plants & habitat | Species-specific | F-sisymbrium | No quantitative safe exposure established here. |
| tumble-mustard-6 | Management & timing | Species-specific | F-sisymbrium | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/index.md
---
{
"id": "velvetleaf",
"name": "Velvetleaf",
"scientific": "Abutilon theophrasti",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Persistent seeds and strong crop competition",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"K-velvetleaf",
"S27",
"Fremont-list-definitions"
],
"description": "Velvetleaf: Persistent seeds and strong crop competition. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"K-velvetleaf"
],
"scope": "Species-specific",
"note": "",
"id": "velvetleaf-1"
},
{
"label": "Plants & habitat",
"sources": [
"K-velvetleaf"
],
"scope": "Species-specific",
"note": "",
"id": "velvetleaf-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "velvetleaf-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "velvetleaf-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "velvetleaf-5"
},
{
"id": "velvetleaf-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"velvetleaf-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"velvetleaf-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"velvetleaf-5"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/velvetleaf.md"
}
---
# Velvetleaf
*Abutilon theophrasti*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Persistent seeds and strong crop competition.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower-leaf** — Small yellow five-petaled flower among broad softly hairy heart-shaped leaves.
Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Abutilon_theophrasti_2015-08-29_5732.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4f/Abutilon_theophrasti_2015-08-29_5732.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**mature-capsules** — Dark cup-like seed capsules arranged along an upright stem beside a heart-shaped leaf.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Abutilon_theophrasti_sl13.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/2/2a/Abutilon_theophrasti_sl13.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Upright branched plant with many large heart-shaped leaves.
Photo: Karelj; [Public domain](https://commons.wikimedia.org/wiki/File:Abutilon_theophrasti_Prague_2017_1.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Abutilon_theophrasti_Prague_2017_1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/77/Abutilon_theophrasti_Prague_2017_1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An upright summer annual with velvety, heart-shaped leaves, yellow five-petaled flowers and a ring-like capsule of pointed segments. [K-velvetleaf](https://cals.cornell.edu/weed-science/weed-profiles/velvetleaf)
## Plants & habitat
A competitive crop weed whose durable seedbank can require years of follow-up. Prevent plants from replenishing seeds. [K-velvetleaf](https://cals.cornell.edu/weed-science/weed-profiles/velvetleaf)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **K-velvetleaf** — [Velvetleaf](https://cals.cornell.edu/weed-science/weed-profiles/velvetleaf), Cornell University College of Agriculture and Life Sciences. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=velvetleaf) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| velvetleaf-1 | Recognize | Species-specific | K-velvetleaf | No quantitative safe exposure established here. |
| velvetleaf-2 | Plants & habitat | Species-specific | K-velvetleaf | No quantitative safe exposure established here. |
| velvetleaf-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| velvetleaf-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| velvetleaf-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md
---
{
"id": "ventenata",
"name": "Ventenata",
"scientific": "Ventenata dubia",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Displaces forage and native grassland",
"warning_tone": "caution",
"aliases": [
"North Africa grass",
"wiregrass",
"softbearded oat grass"
],
"taxonomy_note": "Added to Colorado List A in the rule effective May 15, 2025. Washington’s different legal class is not applied to Colorado.",
"source_ids": [
"CO-rules-2025",
"WA-ventenata",
"S27",
"Fremont-list-definitions"
],
"description": "Ventenata: Displaces forage and native grassland. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"WA-ventenata"
],
"scope": "Species-specific",
"note": "",
"id": "ventenata-1"
},
{
"label": "Plants & habitat",
"sources": [
"WA-ventenata"
],
"scope": "Species-specific",
"note": "",
"id": "ventenata-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "ventenata-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "ventenata-4"
},
{
"label": "Other animals",
"sources": [
"WA-ventenata"
],
"scope": "Species-specific",
"note": "",
"id": "ventenata-5"
},
{
"id": "ventenata-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"ventenata-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"ventenata-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"ventenata-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/ventenata.md"
}
---
# Ventenata
*Ventenata dubia*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Displaces forage and native grassland.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Added to Colorado List A in the rule effective May 15, 2025. Washington’s different legal class is not applied to Colorado.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**inflorescence** — An open, delicate panicle of pale grass spikelets held against a mountain landscape.
Photo: Matt Lavin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/94522064); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/156805499/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Fine grasses require close spikelet and ligule examination. These reference photographs retain the research-grade source identification and should not be used alone as a complete identification key. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habitat** — A dry stand of fine-stemmed grass in an open landscape; broad leaves of other plants occur in the foreground.
Photo: Matt Lavin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/94522064); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/156805502/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Fine grasses require close spikelet and ligule examination. These reference photographs retain the research-grade source identification and should not be used alone as a complete identification key. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**spikelet detail** — Closer view of narrow pale spikelets and fine branches of the panicle.
Photo: Matt Lavin; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/94522064); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/156809120/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Fine grasses require close spikelet and ligule examination. These reference photographs retain the research-grade source identification and should not be used alone as a complete identification key. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A slender winter annual grass with dark stem nodes and an open, branching seedhead; some awns are bent and twisted. [WA-ventenata](https://www.nwcb.wa.gov/weeds/ventenata)
## Plants & habitat
Invades grasslands and hay systems. Seeds move with equipment and hay, and reduced perennial cover can leave soil vulnerable to erosion. [WA-ventenata](https://www.nwcb.wa.gov/weeds/ventenata)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Silica-rich mature growth is poor forage and livestock often avoid it. This does not establish chemical-poisoning safety. [WA-ventenata](https://www.nwcb.wa.gov/weeds/ventenata)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **WA-ventenata** — [Ventenata](https://www.nwcb.wa.gov/weeds/ventenata), Washington State Noxious Weed Control Board. Accessed 2026-09-07T01:09:01+00:00. Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=ventenata) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Added to Colorado List A in the rule effective May 15, 2025. Washington’s different legal class is not applied to Colorado.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| ventenata-1 | Recognize | Species-specific | WA-ventenata | No quantitative safe exposure established here. |
| ventenata-2 | Plants & habitat | Species-specific | WA-ventenata | No quantitative safe exposure established here. |
| ventenata-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| ventenata-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| ventenata-5 | Other animals | Species-specific | WA-ventenata | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/ventenata/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md
---
{
"id": "western-poison-ivy",
"name": "Western poison ivy",
"scientific": "Toxicodendron rydbergii",
"category": "native",
"status": "Colorado native; contact hazard",
"status_sources": [
"C-wetland-guide"
],
"warning": "Skin-rash oil can travel on pet fur",
"warning_tone": "danger",
"aliases": [
"Rydberg’s poison ivy"
],
"taxonomy_note": "The FDA advice covers poison ivy as a group. Source identification distinguishes this western species from other Toxicodendron taxa.",
"source_ids": [
"C-wetland-guide",
"FDA-poison-ivy",
"S27"
],
"description": "Western poison ivy: Skin-rash oil can travel on pet fur. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"C-wetland-guide"
],
"scope": "Species-specific",
"note": "",
"id": "western-poison-ivy-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-wetland-guide"
],
"scope": "Ecology plus site-management inference",
"note": "",
"id": "western-poison-ivy-2"
},
{
"label": "People",
"sources": [
"FDA-poison-ivy"
],
"scope": "Poison-ivy group evidence",
"note": "",
"id": "western-poison-ivy-3"
},
{
"label": "Dogs & cats",
"sources": [
"FDA-poison-ivy"
],
"scope": "Poison-ivy group evidence",
"note": "",
"id": "western-poison-ivy-4"
},
{
"label": "Other animals",
"sources": [
"C-wetland-guide"
],
"scope": "Ecological observation, not feed clearance",
"note": "",
"id": "western-poison-ivy-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"western-poison-ivy-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/western-poison-ivy.md"
}
---
# Western poison ivy
*Toxicodendron rydbergii*
**Colorado native; contact hazard.** [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf)
> **Skin-rash oil can travel on pet fur.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The FDA advice covers poison ivy as a group. Source identification distinguishes this western species from other Toxicodendron taxa.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruit** — Dense cluster of pale whitish berries among dry leaves and twigs.
Photo: Andrey Zharkikh from Salt Lake City, USA; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:2009.09.24_18.43.13_CIMG2618_(6678712231).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/ec/2009.09.24_18.43.13_CIMG2618_%286678712231%29.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Western poison ivy is treated differently in some floras, including within the T. radicans complex. Images are source-identified T. rydbergii; a three-leaflet leaf by itself is not species-specific. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Branching clusters of tiny pale yellow-green flowers beside young stems.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Toxicodendron_rydbergii_2_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d6/Toxicodendron_rydbergii_2_RF.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Western poison ivy is treated differently in some floras, including within the T. radicans complex. Images are source-identified T. rydbergii; a three-leaflet leaf by itself is not species-specific. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit-foliage** — Low patch of woody shoots bearing groups of three broad green leaflets.
Photo: Robert Flogaus-Faust; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Toxicodendron_rydbergii_RF.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/14/Toxicodendron_rydbergii_RF.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Western poison ivy is treated differently in some floras, including within the T. radicans complex. Images are source-identified T. rydbergii; a three-leaflet leaf by itself is not species-specific. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A low shrub with leaves divided into three leaflets and pale fruits. Colorado’s regional flora identifies this native species. [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf)
## Plants & habitat
Spreads through underground growth. Its native ecological role does not remove the need to manage contact near paths and play areas. [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf)
*Evidence scope: Ecology plus site-management inference.*
## People
Urushiol oil can cause an itchy rash and remain on tools or clothing. Smoke from burning poison ivy is hazardous; do not burn it. [FDA-poison-ivy](https://www.fda.gov/consumers/consumer-updates/outsmarting-poison-ivy-and-other-poisonous-plants)
*Evidence scope: Poison-ivy group evidence.*
## Dogs & cats
Most pets are less sensitive to the oil, but fur can carry it to people. Avoid barehanded contact with exposed fur and get advice on safe cleaning. [FDA-poison-ivy](https://www.fda.gov/consumers/consumer-updates/outsmarting-poison-ivy-and-other-poisonous-plants)
*Evidence scope: Poison-ivy group evidence.*
## Other animals
The Colorado flora describes wildlife browsing. This does not establish safe feed quantities for livestock or pets. [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf)
*Evidence scope: Ecological observation, not feed clearance.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-wetland-guide** — [Common Wetland Plants of Colorado’s Western Slope](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf), Colorado Natural Heritage Program / Colorado State University. Accessed 2026-09-07T01:14:13+00:00. Locator: Water hemlock and western poison ivy entries; taxonomic scope.
- **FDA-poison-ivy** — [Outsmarting Poison Ivy and Other Poisonous Plants](https://www.fda.gov/consumers/consumer-updates/outsmarting-poison-ivy-and-other-poisonous-plants), US Food and Drug Administration. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=western-poison-ivy) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The FDA advice covers poison ivy as a group. Source identification distinguishes this western species from other Toxicodendron taxa.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| western-poison-ivy-1 | Recognize | Species-specific | C-wetland-guide | No quantitative safe exposure established here. |
| western-poison-ivy-2 | Plants & habitat | Ecology plus site-management inference | C-wetland-guide | No quantitative safe exposure established here. |
| western-poison-ivy-3 | People | Poison-ivy group evidence | FDA-poison-ivy | No quantitative safe exposure established here. |
| western-poison-ivy-4 | Dogs & cats | Poison-ivy group evidence | FDA-poison-ivy | No quantitative safe exposure established here. |
| western-poison-ivy-5 | Other animals | Ecological observation, not feed clearance | C-wetland-guide | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md
---
{
"id": "western-ragweed",
"name": "Western ragweed",
"scientific": "Ambrosia psilostachya",
"category": "native",
"status": "Native Colorado plant · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A persistent perennial ragweed; allergy detail still under review",
"warning_tone": "caution",
"aliases": [
"Cuman ragweed",
"perennial ragweed"
],
"taxonomy_note": "Unlike annual common and giant ragweeds, this species is perennial. Ambrosia psilostachya is not treated as a synonym of either.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-ambrosia-psilostachya",
"C-ragweed-native",
"S27"
],
"description": "Western ragweed: A persistent perennial ragweed; allergy detail still under review. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-ambrosia-psilostachya"
],
"scope": "Species-specific",
"note": "",
"id": "western-ragweed-1"
},
{
"label": "People",
"sources": [
"C-ragweed-native"
],
"scope": "Related-species context; species-specific evidence unresolved",
"note": "",
"id": "western-ragweed-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "western-ragweed-3"
},
{
"label": "Other animals",
"sources": [
"F-ambrosia-psilostachya"
],
"scope": "Species forage discussion; broader treated-ragweed warning",
"note": "",
"id": "western-ragweed-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-ambrosia-psilostachya"
],
"scope": "Species-specific",
"note": "",
"id": "western-ragweed-5"
},
{
"label": "Management & timing",
"sources": [
"F-ambrosia-psilostachya"
],
"scope": "Management inference from perennial growth",
"note": "",
"id": "western-ragweed-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"western-ragweed-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"western-ragweed-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"western-ragweed-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 32; Ambrosia psilostachya",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Ambrosia psilostachya"
},
"source": "content/plants/western-ragweed.md"
}
---
# Western ragweed
*Ambrosia psilostachya*
**Native Colorado plant · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A persistent perennial ragweed; allergy detail still under review.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Unlike annual common and giant ragweeds, this species is perennial. Ambrosia psilostachya is not treated as a synonym of either.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright western ragweed stems with divided green leaves and elongated terminal flower spikes.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/179141365); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/311838775/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**male-flower-heads** — Close view of small green, downward-facing male flower heads along a western ragweed spike.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/179141365); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/312069077/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf-surface** — Close view of the hairy surface and narrow lobes of a western ragweed leaf.
Photo: Zihao Wang; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/179141365); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/312069114/original.jpeg). Explicit iNaturalist observation taxon and Research Grade community identification; photograph visually reviewed for depicted features. This is source identification, not a new independent botanical determination. Source identifies this plant to species; no variety or subspecies determination is asserted. Downloaded iNaturalist large rendition; downloaded bytes retained unchanged. No local crop, retouching, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A native perennial with relatively slender branching stems and an extensive underground system. Male flower heads occur at the tips; female flowers occur in leaf axils. [F-ambrosia-psilostachya](https://research.fs.usda.gov/feis/species-reviews/ambpsi)
## People
Ragweeds are associated with allergenic windborne pollen. The reviewed Colorado allergy discussion focuses on common and giant ragweed; western ragweed-specific allergy severity still needs review. [C-ragweed-native](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf)
*Evidence scope: Related-species context; species-specific evidence unresolved.*
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The Forest Service describes forage and wildlife use and does not classify the untreated plant as poisonous in that discussion. It separately reports possible nitrate accumulation in herbicide-treated ragweeds; a safe feeding amount is not established. [F-ambrosia-psilostachya](https://research.fs.usda.gov/feis/species-reviews/ambpsi)
*Evidence scope: Species forage discussion; broader treated-ragweed warning.*
## Plants & habitat
It occupies native grasslands and disturbed sites and provides food or cover for birds and small mammals. Underground spread can make garden colonies persistent. [F-ambrosia-psilostachya](https://research.fs.usda.gov/feis/species-reviews/ambpsi)
## Management & timing
Plan follow-up for underground regrowth. Seed prevention alone does not address an established perennial colony. [F-ambrosia-psilostachya](https://research.fs.usda.gov/feis/species-reviews/ambpsi)
*Evidence scope: Management inference from perennial growth.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-ambrosia-psilostachya** — [Western ragweed](https://research.fs.usda.gov/feis/species-reviews/ambpsi), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:49+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **C-ragweed-native** — [Ragweed](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf), Colorado State University Extension. Accessed 2026-09-07T02:26:09+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=western-ragweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 32; Ambrosia psilostachya. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Unlike annual common and giant ragweeds, this species is perennial. Ambrosia psilostachya is not treated as a synonym of either.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| western-ragweed-1 | Identification | Species-specific | F-ambrosia-psilostachya | No quantitative safe exposure established here. |
| western-ragweed-2 | People | Related-species context; species-specific evidence unresolved | C-ragweed-native | No quantitative safe exposure established here. |
| western-ragweed-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| western-ragweed-4 | Other animals | Species forage discussion; broader treated-ragweed warning | F-ambrosia-psilostachya | No quantitative safe exposure established here. |
| western-ragweed-5 | Plants & habitat | Species-specific | F-ambrosia-psilostachya | No quantitative safe exposure established here. |
| western-ragweed-6 | Management & timing | Management inference from perennial growth | F-ambrosia-psilostachya | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md
---
{
"id": "western-water-hemlock",
"name": "Western water hemlock",
"scientific": "Cicuta douglasii",
"category": "native",
"status": "Native wetland hazard; not an A/B/C listing in the reviewed rule",
"status_sources": [
"C-wetland-guide",
"CO-rules-2025"
],
"warning": "Potentially fatal poisoning; wetland look-alike danger",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "The older Colorado wetland guide treats C. douglasii within C. maculata var. angustifolia. The photos and Utah source identify C. douglasii. This is separate from poison hemlock (Conium maculatum). Older home-treatment instructions and an incorrect chemical classification in sources are excluded.",
"source_ids": [
"C-wetland-guide",
"CO-rules-2025",
"U-water-hemlock",
"C-routt-guide",
"S27"
],
"description": "Western water hemlock: Potentially fatal poisoning; wetland look-alike danger. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"U-water-hemlock"
],
"scope": "Species-specific",
"note": "",
"id": "western-water-hemlock-1"
},
{
"label": "Plants & habitat",
"sources": [
"C-wetland-guide"
],
"scope": "Older regional flora; taxonomic scope differs",
"note": "",
"id": "western-water-hemlock-2"
},
{
"label": "People",
"sources": [
"C-routt-guide"
],
"scope": "Species-specific",
"note": "",
"id": "western-water-hemlock-3"
},
{
"label": "Dogs & cats",
"sources": [
"C-routt-guide"
],
"scope": "Dog warning; cat evidence gap",
"note": "",
"id": "western-water-hemlock-4"
},
{
"label": "Other animals",
"sources": [
"U-water-hemlock"
],
"scope": "Species-specific",
"note": "",
"id": "western-water-hemlock-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"western-water-hemlock-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/western-water-hemlock.md"
}
---
# Western water hemlock
*Cicuta douglasii*
**Native wetland hazard; not an A/B/C listing in the reviewed rule.** [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Potentially fatal poisoning; wetland look-alike danger.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The older Colorado wetland guide treats C. douglasii within C. maculata var. angustifolia. The photos and Utah source identify C. douglasii. This is separate from poison hemlock (Conium maculatum). Older home-treatment instructions and an incorrect chemical classification in sources are excluded.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Upright leafy stems with pinnately divided, sharply toothed leaflets.
Photo: Lee Cain; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cicuta_douglasii_284166253.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/18/Cicuta_douglasii_284166253.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Water-hemlock species are difficult to distinguish in general photographs. These references are explicitly source-identified C. douglasii; they are not proof that an unknown water-hemlock belongs to this species. C. maculata and related taxa require a regional botanical key and reproductive details. Comparison images also showing Conium were excluded. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower** — Rounded clusters of pale flowers and developing fruits form a compound umbel.
Photo: Matt Berger; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cicuta_douglasii_442485760.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/eb/Cicuta_douglasii_442485760.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Water-hemlock species are difficult to distinguish in general photographs. These references are explicitly source-identified C. douglasii; they are not proof that an unknown water-hemlock belongs to this species. C. maculata and related taxa require a regional botanical key and reproductive details. Comparison images also showing Conium were excluded. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Pinnately arranged lance-shaped leaflets with sharply toothed margins and visible side veins.
Photo: N5jrn; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cicuta_douglasii_leaf_detail.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c7/Cicuta_douglasii_leaf_detail.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Water-hemlock species are difficult to distinguish in general photographs. These references are explicitly source-identified C. douglasii; they are not proof that an unknown water-hemlock belongs to this species. C. maculata and related taxa require a regional botanical key and reproductive details. Comparison images also showing Conium were excluded. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A wetland perennial with clusters of small white flowers and divided leaves; veins terminate in notches between the leaflet teeth. Never taste, cut roots or use this short description as a foraging test. [U-water-hemlock](https://extension.usu.edu/rangeplants/forbs-herbaceous/water-hemlock)
## Plants & habitat
Occurs around wet ground, ditches and waterways. Colorado floras have used broader Cicuta names for related populations. [C-wetland-guide](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf)
*Evidence scope: Older regional flora; taxonomic scope differs.*
## People
Routt County identifies water hemlock as a potentially lethal poison. Treat suspected ingestion as an emergency. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
## Dogs & cats
The county guide explicitly warns about dogs. Cat-specific clinical detail is not established here; keep all pets away from chewing plants or exposed roots. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)
*Evidence scope: Dog warning; cat evidence gap.*
## Other animals
Highly poisonous to livestock, especially the roots. Convulsions and death can follow ingestion. [U-water-hemlock](https://extension.usu.edu/rangeplants/forbs-herbaceous/water-hemlock)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-wetland-guide** — [Common Wetland Plants of Colorado’s Western Slope](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf), Colorado Natural Heritage Program / Colorado State University. Accessed 2026-09-07T01:14:13+00:00. Locator: Water hemlock and western poison ivy entries; taxonomic scope.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **U-water-hemlock** — [Water Hemlock](https://extension.usu.edu/rangeplants/forbs-herbaceous/water-hemlock), Utah State University Extension. Accessed 2026-09-07T01:14:00+00:00. Locator: Cicuta douglasii identification and toxicity.
- **C-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=western-water-hemlock) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
The older Colorado wetland guide treats C. douglasii within C. maculata var. angustifolia. The photos and Utah source identify C. douglasii. This is separate from poison hemlock (Conium maculatum). Older home-treatment instructions and an incorrect chemical classification in sources are excluded.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| western-water-hemlock-1 | Recognize | Species-specific | U-water-hemlock | No quantitative safe exposure established here. |
| western-water-hemlock-2 | Plants & habitat | Older regional flora; taxonomic scope differs | C-wetland-guide | No quantitative safe exposure established here. |
| western-water-hemlock-3 | People | Species-specific | C-routt-guide | No quantitative safe exposure established here. |
| western-water-hemlock-4 | Dogs & cats | Dog warning; cat evidence gap | C-routt-guide | No quantitative safe exposure established here. |
| western-water-hemlock-5 | Other animals | Species-specific | U-water-hemlock | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md
---
{
"id": "western-whorled-milkweed",
"name": "Western whorled milkweed",
"scientific": "Asclepias subverticillata",
"category": "native",
"status": "Colorado native",
"status_sources": [
"S06"
],
"warning": "High livestock toxicity",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"S06",
"S05",
"S04"
],
"description": "Western whorled milkweed: High livestock toxicity. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"S06"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "western-whorled-milkweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"S06"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "western-whorled-milkweed-2"
},
{
"label": "People",
"sources": [
"S05"
],
"scope": "Genus-level",
"note": "",
"reviewed": "2026-09-06",
"id": "western-whorled-milkweed-3"
},
{
"label": "Dogs & cats",
"sources": [
"S04"
],
"scope": "Genus-level",
"note": "",
"reviewed": "2026-09-06",
"id": "western-whorled-milkweed-4"
},
{
"label": "Other animals",
"sources": [
"S06"
],
"scope": "Species-specific",
"note": "",
"reviewed": "2026-09-06",
"id": "western-whorled-milkweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/western-whorled-milkweed.md"
}
---
# Western whorled milkweed
*Asclepias subverticillata*
**Colorado native.** [S06](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/)
> **High livestock toxicity.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flowering stems** — Several slender flowering stems with small white umbels and very narrow leaves.
Photo: Patrick Alexander from Las Cruces, NM; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Asclepias_subverticillata_-_Flickr_-_aspidoscelis.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0b/Asclepias_subverticillata_-_Flickr_-_aspidoscelis.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit and habitat** — A patch of slender horsetail milkweed stems among grasses, with white flower clusters held above the narrow foliage.
Photo: Patrick Alexander from Las Cruces, NM; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Asclepias_subverticillata_-_Flickr_-_aspidoscelis_(1).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/cc/Asclepias_subverticillata_-_Flickr_-_aspidoscelis_%281%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower detail** — Close view of white milkweed flowers with reflexed petals, small upright hoods, and adjacent linear leaves.
Photo: Patrick Alexander from Las Cruces, NM; [CC0](https://creativecommons.org/publicdomain/zero/1.0/deed.en); [source record](https://commons.wikimedia.org/wiki/File:Asclepias_subverticillata_-_Flickr_-_aspidoscelis_(3).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/54/Asclepias_subverticillata_-_Flickr_-_aspidoscelis_%283%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Slender upright stems, very narrow leaves in rings of 3–5, and greenish-white flower clusters. Common at lower Colorado elevations. [S06](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/)
## Plants & habitat
Spreads by roots and seed into gardens and pasture. Also hosts monarch and queen butterfly caterpillars. [S06](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/)
## People
Avoid ingestion and sap contact. Human precautions here come from milkweed guidance for the genus, not a species-specific human study. [S05](https://www.poison.org/articles/milkweed-can-cause-serious-poisoning-204)
*Evidence scope: Genus-level.*
## Dogs & cats
ASPCA lists milkweeds as toxic to dogs and cats. This source does not give a safe amount for this species. [S04](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed)
*Evidence scope: Genus-level.*
## Other animals
Highly toxic to livestock. Dry plants remain hazardous in hay; a butterfly benefit does not make it suitable near grazing animals. [S06](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **S06** — [Managing Western Whorled Milkweed](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/), Colorado State University Extension. Accessed 2026-09-07T00:23:53+00:00. Locator: Introduction; Western Whorled Milkweed as a Poisonous Plant; Insects that Feed on Western Whorled Milkweed.
- **S05** — [Milkweed plants can cause serious poisoning](https://www.poison.org/articles/milkweed-can-cause-serious-poisoning-204), National Capital Poison Center. Accessed 2026-09-07T00:23:53+00:00. Locator: Symptoms; Effects on skin and in eyes; prevention.
- **S04** — [Milkweed](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed), ASPCA Poison Control. Accessed 2026-09-07T00:23:52+00:00. Locator: Scientific Name; Toxicity; Clinical Signs; poison contact.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=western-whorled-milkweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Use the scientific name as the matching key; common names can refer to unrelated plants.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| western-whorled-milkweed-1 | Recognize | Species-specific | S06 | No quantitative exposure threshold established here. |
| western-whorled-milkweed-2 | Plants & habitat | Species-specific | S06 | No quantitative exposure threshold established here. |
| western-whorled-milkweed-3 | People | Genus-level | S05 | No quantitative exposure threshold established here. |
| western-whorled-milkweed-4 | Dogs & cats | Genus-level | S04 | No quantitative exposure threshold established here. |
| western-whorled-milkweed-5 | Other animals | Species-specific | S06 | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/white-clover/index.md
---
{
"id": "white-clover",
"name": "White clover",
"scientific": "Trifolium repens",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "A spreading lawn plant with pollinator value",
"warning_tone": "caution",
"aliases": [
"Dutch clover",
"ladino clover"
],
"taxonomy_note": "White clover (Trifolium repens) differs from white sweetclover (Melilotus albus); the moldy sweetclover-hay warning is not assigned to it solely from a common name.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-trifolium-repens",
"C-descriptions",
"S27"
],
"description": "White clover: A spreading lawn plant with pollinator value. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-trifolium-repens"
],
"scope": "Species-specific",
"note": "",
"id": "white-clover-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "white-clover-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "white-clover-3"
},
{
"label": "Other animals",
"sources": [
"N-trifolium-repens"
],
"scope": "Forage-use observation; safety limitation",
"note": "",
"id": "white-clover-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-trifolium-repens"
],
"scope": "Species-specific",
"note": "",
"id": "white-clover-5"
},
{
"label": "Management & timing",
"sources": [
"N-trifolium-repens",
"C-descriptions"
],
"scope": "Species-specific",
"note": "",
"id": "white-clover-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"white-clover-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"white-clover-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"white-clover-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 84; Trifolium repens",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Trifolium repens"
},
"source": "content/plants/white-clover.md"
}
---
# White clover
*Trifolium repens*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **A spreading lawn plant with pollinator value.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** White clover (Trifolium repens) differs from white sweetclover (Melilotus albus); the moldy sweetclover-hay warning is not assigned to it solely from a common name.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — A rounded flower head of small white pea-like florets on a slender stalk.
Photo: Ivar Leidus; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Trifolium_repens_inflorescence_-_Niitv%C3%A4lja.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0d/Trifolium_repens_inflorescence_-_Niitv%C3%A4lja.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified T. repens. Leaf markings can vary or be absent; three leaflets and pale crescents alone do not establish a specimen’s identity or cultivar. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — A dense low rounded patch of white clover with many pale flower heads in grass.
Photo: H. Zell; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Trifolium_repens_001.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f4/Trifolium_repens_001.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified T. repens. Leaf markings can vary or be absent; three leaflets and pale crescents alone do not establish a specimen’s identity or cultivar. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**mature-head** — A mature drooping flower head with brown papery florets beneath green calyces, photographed with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Trifolium_repens_(subsp._repens)_sl10.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/0a/Trifolium_repens_%28subsp._repens%29_sl10.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified T. repens. Leaf markings can vary or be absent; three leaflets and pale crescents alone do not establish a specimen’s identity or cultivar. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A low perennial with three leaflets, often bearing pale crescents, and rounded heads of white flowers. Runners root at their joints. [N-trifolium-repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
It is grown as livestock forage. This botanical description is not a complete feeding-risk assessment and gives no safe ration. [N-trifolium-repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/)
*Evidence scope: Forage-use observation; safety limitation.*
## Plants & habitat
White clover fixes nitrogen, attracts pollinators and spreads in lawns. Whether it is a weed depends on the intended planting. [N-trifolium-repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/)
## Management & timing
First decide whether the clover is unwanted. Its creeping stems can tolerate mowing; manage lawn conditions if trying to favor turf. [N-trifolium-repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/) [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-trifolium-repens** — [Trifolium repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=white-clover) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 84; Trifolium repens. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
White clover (Trifolium repens) differs from white sweetclover (Melilotus albus); the moldy sweetclover-hay warning is not assigned to it solely from a common name.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| white-clover-1 | Identification | Species-specific | N-trifolium-repens | No quantitative safe exposure established here. |
| white-clover-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| white-clover-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| white-clover-4 | Other animals | Forage-use observation; safety limitation | N-trifolium-repens | No quantitative safe exposure established here. |
| white-clover-5 | Plants & habitat | Species-specific | N-trifolium-repens | No quantitative safe exposure established here. |
| white-clover-6 | Management & timing | Species-specific | N-trifolium-repens, C-descriptions | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/white-clover/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/white-clover/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/white-clover/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md
---
{
"id": "white-locoweed",
"name": "White locoweed",
"scientific": "Oxytropis sericea",
"category": "native",
"status": "Colorado native",
"status_sources": [
"F-locoweed"
],
"warning": "Toxic to livestock",
"warning_tone": "danger",
"aliases": [
"silky crazyweed",
"whitepoint locoweed"
],
"taxonomy_note": "The USFS synthesis dates to 1993; its taxonomy and cited studies are retained as historical evidence. No pet dose is inferred from livestock studies.",
"source_ids": [
"F-locoweed",
"A-loco"
],
"description": "White locoweed: Toxic to livestock. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"F-locoweed"
],
"scope": "Species-specific",
"note": "",
"id": "white-locoweed-1"
},
{
"label": "Plants & habitat",
"sources": [
"F-locoweed"
],
"scope": "Species-specific",
"note": "",
"id": "white-locoweed-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human exposure effects were not established in the reviewed livestock sources; this is not a food plant recommendation.",
"id": "white-locoweed-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "white-locoweed-4"
},
{
"label": "Other animals",
"sources": [
"F-locoweed",
"A-loco"
],
"scope": "Species-specific persistence; locoweed-group clinical effects",
"note": "",
"id": "white-locoweed-5"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"white-locoweed-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"white-locoweed-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"source": "content/plants/white-locoweed.md"
}
---
# White locoweed
*Oxytropis sericea*
**Colorado native.** [F-locoweed](https://research.fs.usda.gov/feis/species-reviews/oxyser)
> **Toxic to livestock.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** The USFS synthesis dates to 1993; its taxonomy and cited studies are retained as historical evidence. No pet dose is inferred from livestock studies.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**seed pods** — Dry tan pods clustered along a stalk, some split open near their tips.
Photo: Matt Lavin from Bozeman, Montana, USA; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Oxytropis_sericea_(7352491560).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/8/87/Oxytropis_sericea_%287352491560%29.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowers and foliage** — A flowering patch with numerous upright clusters of white pea-shaped flowers and pinnate leaves below.
Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Oxytropis_sericea_1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/7/74/Oxytropis_sericea_1.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**whole plant** — Low pinnate foliage and several erect stalks of pale flowers growing from gravelly ground.
Photo: Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Oxytropis_sericea_kz01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/ad/Oxytropis_sericea_kz01.jpg). Wikimedia Commons source file title and species metadata identify the taxon. Visible morphology was checked for consistency, not treated as an independent botanical determination. No edits to the downloaded image. Wikimedia may have supplied a scaled thumbnail; original and download URLs are recorded separately. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A low perennial with pinnately compound leaves and pale pea-like flowers; use a botanical key to separate similar locoweeds. [F-locoweed](https://research.fs.usda.gov/feis/species-reviews/oxyser)
## Plants & habitat
Native on open western plains and mountain sites, with persistent seed banks. Occurrence alone is not proof of an invasive-weed problem. [F-locoweed](https://research.fs.usda.gov/feis/species-reviews/oxyser)
## People
Human exposure effects were not established in the reviewed livestock sources; this is not a food plant recommendation. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
Locoweeds can cause neurological damage, wasting and reproductive harm in livestock, including horses. White locoweed remains poisonous when dried. Keep it out of feed and seek livestock-veterinary advice. [F-locoweed](https://research.fs.usda.gov/feis/species-reviews/oxyser) [A-loco](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/locoweed-astragalus-and-oxytropis-spp/)
*Evidence scope: Species-specific persistence; locoweed-group clinical effects.*
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **F-locoweed** — [Oxytropis sericea species review](https://research.fs.usda.gov/feis/species-reviews/oxyser), US Forest Service. Accessed 2026-09-07T00:27:18+00:00. Locator: Description, distribution, hazards, management; see claim locator.
- **A-loco** — [Locoweed (Astragalus and Oxytropis spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/locoweed-astragalus-and-oxytropis-spp/), USDA Agricultural Research Service. Accessed 2026-09-07T00:27:18+00:00. Locator: Description, distribution, hazards, management; see claim locator.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=white-locoweed) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
The USFS synthesis dates to 1993; its taxonomy and cited studies are retained as historical evidence. No pet dose is inferred from livestock studies.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| white-locoweed-1 | Recognize | Species-specific | F-locoweed | No quantitative exposure threshold established here. |
| white-locoweed-2 | Plants & habitat | Species-specific | F-locoweed | No quantitative exposure threshold established here. |
| white-locoweed-3 | People | Review limitation | Review limitation | Human exposure effects were not established in the reviewed livestock sources; this is not a food plant recommendation. |
| white-locoweed-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| white-locoweed-5 | Other animals | Species-specific persistence; locoweed-group clinical effects | F-locoweed, A-loco | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/
Content revised: 2026-09-07T02:43:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md
---
{
"id": "white-sweetclover",
"name": "White sweetclover",
"scientific": "Melilotus albus",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Moldy sweetclover hay can cause dangerous bleeding",
"warning_tone": "caution",
"aliases": [
"Melilotus alba",
"white sweet clover"
],
"taxonomy_note": "Older sources often spell the name Melilotus alba. This is not white clover (Trifolium repens). Sweetclover hay warnings are specific to the documented feed conditions, not a pet dose calculation.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"F-melilotus",
"S27"
],
"description": "White sweetclover: Moldy sweetclover hay can cause dangerous bleeding. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"F-melilotus"
],
"scope": "Species-specific",
"note": "",
"id": "white-sweetclover-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "white-sweetclover-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "white-sweetclover-3"
},
{
"label": "Other animals",
"sources": [
"F-melilotus"
],
"scope": "Sweetclover group evidence",
"note": "",
"id": "white-sweetclover-4"
},
{
"label": "Plants & habitat",
"sources": [
"F-melilotus"
],
"scope": "Species-specific",
"note": "",
"id": "white-sweetclover-5"
},
{
"label": "Management & timing",
"sources": [
"F-melilotus"
],
"scope": "Management synthesis",
"note": "",
"id": "white-sweetclover-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"white-sweetclover-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"white-sweetclover-3"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 63; Melilotus albus",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Melilotus albus"
},
"source": "content/plants/white-sweetclover.md"
}
---
# White sweetclover
*Melilotus albus*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Moldy sweetclover hay can cause dangerous bleeding.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Older sources often spell the name Melilotus alba. This is not white clover (Trifolium repens). Sweetclover hay warnings are specific to the documented feed conditions, not a pet dose calculation.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowers and leaves** — Small white flowers on slender racemes above three-part leaves.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/258673179); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/464161778/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source. White flowers, three-part leaves and pods are shown; no yellow-flowered sweetclover was substituted. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**pods** — Small oval green pods along slender branching stems.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/258673179); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/464162009/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source. White flowers, three-part leaves and pods are shown; no yellow-flowered sweetclover was substituted. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leafy flowering shoot** — A leafy shoot with three-part, toothed leaflets and narrow racemes of small white flowers.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/258673179); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/464162032/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Identification follows the source. White flowers, three-part leaves and pods are shown; no yellow-flowered sweetclover was substituted. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
Usually a tall biennial with three leaflets and long clusters of small white flowers. Fresh flowers distinguish it from yellow sweetclover; dried flowers may be misleading. [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Moldy or improperly cured sweetclover hay can cause impaired clotting and fatal bleeding. Diets dominated by sweetclover may also cause bloat. [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
*Evidence scope: Sweetclover group evidence.*
## Plants & habitat
A nonnative legume that supplies forage and pollinator resources but can spread into disturbed and natural vegetation. [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
## Management & timing
Prevent seed production where unwanted and monitor subsequent seedlings. Have suspect hay assessed before feeding. [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **F-melilotus** — [White and yellow sweetclover](https://research.fs.usda.gov/feis/species-reviews/melspp), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:26:14+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=white-sweetclover) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 63; Melilotus albus. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Older sources often spell the name Melilotus alba. This is not white clover (Trifolium repens). Sweetclover hay warnings are specific to the documented feed conditions, not a pet dose calculation.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| white-sweetclover-1 | Identification | Species-specific | F-melilotus | No quantitative safe exposure established here. |
| white-sweetclover-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| white-sweetclover-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| white-sweetclover-4 | Other animals | Sweetclover group evidence | F-melilotus | No quantitative safe exposure established here. |
| white-sweetclover-5 | Plants & habitat | Species-specific | F-melilotus | No quantitative safe exposure established here. |
| white-sweetclover-6 | Management & timing | Management synthesis | F-melilotus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/index.md
---
{
"id": "wild-caraway",
"name": "Wild caraway",
"scientific": "Carum carvi",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Spreads by seed; pet safety concern",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "A white flower umbrella is not sufficient to separate caraway from poison hemlock or water hemlock; the comparison is an editorial identification precaution.",
"source_ids": [
"CO-rules-2025",
"N-carum-carvi",
"S27",
"A-caraway",
"Fremont-list-definitions"
],
"description": "Wild caraway: Spreads by seed; pet safety concern. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-carum-carvi"
],
"scope": "Species-specific",
"note": "",
"id": "wild-caraway-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-carum-carvi"
],
"scope": "Species-specific",
"note": "",
"id": "wild-caraway-2"
},
{
"label": "People",
"sources": [
"N-carum-carvi"
],
"scope": "Editorial identification precaution",
"note": "",
"id": "wild-caraway-3"
},
{
"label": "Dogs & cats",
"sources": [
"A-caraway"
],
"scope": "Species-specific",
"note": "",
"id": "wild-caraway-4"
},
{
"label": "Other animals",
"sources": [
"A-caraway"
],
"scope": "Species-specific",
"note": "",
"id": "wild-caraway-5"
},
{
"id": "wild-caraway-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"wild-caraway-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/wild-caraway.md"
}
---
# Wild caraway
*Carum carvi*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spreads by seed; pet safety concern.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** A white flower umbrella is not sufficient to separate caraway from poison hemlock or water hemlock; the comparison is an editorial identification precaution.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**fruits** — Developing ribbed caraway fruits on the radiating stalks of a compound umbel.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carum_carvi_15-p.bot-carum.carvi-24.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/56/Carum_carvi_15-p.bot-carum.carvi-24.jpg). Source-identified photograph with visual consistency check Nom français : carvi commun. Nom anglais : wild caraway. Infrutescence (ombelle composée, ombellules, fruits, diachaines) de carvi commun, vue de côté. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — White-flowering caraway plants growing as a patch beside a fence in grassland.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carum_carvi_15-p.bot-carum.carvi-29.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/6a/Carum_carvi_15-p.bot-carum.carvi-29.jpg). Source-identified photograph with visual consistency check Nom français : carvi commun. Nom anglais : wild caraway. Plants en fleur (inflorescence) de carvi commun, en milieu naturel. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaves** — Several finely divided caraway leaves displayed against a dark background.
Photo: Ayotte, Gilles, 1948-; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Carum_carvi_15-p.bot-carum.carvi-08.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/e/e3/Carum_carvi_15-p.bot-carum.carvi-08.jpg). Source-identified photograph with visual consistency check Nom français : carvi commun. Nom anglais : wild caraway. Feuilles de carvi commun. Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A biennial with finely divided, carrot-like leaves and small white or pinkish flowers in umbrella-shaped clusters. [N-carum-carvi](https://plants.ces.ncsu.edu/plants/carum-carvi/)
## Plants & habitat
Self-sows in suitable moist sites. Culinary use does not remove its Colorado weed designation. [N-carum-carvi](https://plants.ces.ncsu.edu/plants/carum-carvi/)
## People
White-flowered carrot-family plants require careful identification. The caraway description is not enough to rule out poisonous look-alikes. [N-carum-carvi](https://plants.ces.ncsu.edu/plants/carum-carvi/)
*Evidence scope: Editorial identification precaution.*
## Dogs & cats
ASPCA lists Carum carvi as toxic to dogs and cats, with vomiting and diarrhea associated with its oils. No safe dose is established here. [A-caraway](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/caraway)
## Other animals
ASPCA also lists horses as susceptible. Culinary use by people does not establish forage safety. [A-caraway](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/caraway)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-carum-carvi** — [carum carvi — Plant Toolbox](https://plants.ces.ncsu.edu/plants/carum-carvi/), NC State Extension. Accessed 2026-09-07T01:04:54+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
- **A-caraway** — [Caraway](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/caraway), ASPCA Poison Control. Accessed 2026-09-07T01:14:01+00:00. Locator: Scientific name and toxicity.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=wild-caraway) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
A white flower umbrella is not sufficient to separate caraway from poison hemlock or water hemlock; the comparison is an editorial identification precaution.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| wild-caraway-1 | Recognize | Species-specific | N-carum-carvi | No quantitative safe exposure established here. |
| wild-caraway-2 | Plants & habitat | Species-specific | N-carum-carvi | No quantitative safe exposure established here. |
| wild-caraway-3 | People | Editorial identification precaution | N-carum-carvi | No quantitative safe exposure established here. |
| wild-caraway-4 | Dogs & cats | Species-specific | A-caraway | No quantitative safe exposure established here. |
| wild-caraway-5 | Other animals | Species-specific | A-caraway | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/index.md
---
{
"id": "wild-carrot",
"name": "Wild carrot",
"scientific": "Daucus carota",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Do not confuse it with highly poisonous hemlocks",
"warning_tone": "caution",
"aliases": [
"Queen Anne’s lace",
"Queen Anne's lace"
],
"taxonomy_note": "Wild carrot, poison hemlock and water hemlocks require careful separation. A dark floret, a smell or a photograph by itself is insufficient. This profile does not authorize eating wild roots.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-daucus-carota",
"S27"
],
"description": "Wild carrot: Do not confuse it with highly poisonous hemlocks. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-daucus-carota"
],
"scope": "Species-specific",
"note": "",
"id": "wild-carrot-1"
},
{
"label": "People",
"sources": [
"N-daucus-carota"
],
"scope": "Species contact hazard; identification precaution",
"note": "",
"id": "wild-carrot-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-carrot-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-carrot-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-daucus-carota"
],
"scope": "Species-specific",
"note": "",
"id": "wild-carrot-5"
},
{
"label": "Management & timing",
"sources": [
"N-daucus-carota"
],
"scope": "Management inference from reproduction and sap hazard",
"note": "",
"id": "wild-carrot-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"wild-carrot-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"wild-carrot-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 48; Daucus carota",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Daucus carota"
},
"source": "content/plants/wild-carrot.md"
}
---
# Wild carrot
*Daucus carota*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Do not confuse it with highly poisonous hemlocks.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Wild carrot, poison hemlock and water hemlocks require careful separation. A dark floret, a smell or a photograph by itself is insufficient. This profile does not authorize eating wild roots.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering umbel** — A white compound umbel with a dark central flower and radiating flower clusters; the source identifies Daucus carota carota.
Photo: zebedeugalinha; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/371801398); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/679335953/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Photo 11-01 is source-identified Daucus carota carota; the other sources use Daucus carota. Exact names are preserved. Similar white-flowered umbellifers require a full key; a dark central flower alone is not sufficient. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**leaf** — A finely divided compound leaf with narrow pointed segments on a visibly hairy stalk.
Photo: Eleftherios Katsillis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/71074966); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/115648147/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Photo 11-01 is source-identified Daucus carota carota; the other sources use Daucus carota. Exact names are preserved. Similar white-flowered umbellifers require a full key; a dark central flower alone is not sufficient. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — An upright branching flowering plant with white umbels growing among grasses.
Photo: Eleftherios Katsillis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/71074966); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/115648319/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Photo 11-01 is source-identified Daucus carota carota; the other sources use Daucus carota. Exact names are preserved. Similar white-flowered umbellifers require a full key; a dark central flower alone is not sufficient. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A biennial with finely divided leaves, bristly stems and white flower umbels. These clues alone are not a safe identification key. [N-daucus-carota](https://plants.ces.ncsu.edu/plants/daucus-carota/)
## People
Sap may cause dermatitis, including reactions in light. Do not taste an unidentified carrot-family plant; this guide is not a foraging identification service. [N-daucus-carota](https://plants.ces.ncsu.edu/plants/daucus-carota/)
*Evidence scope: Species contact hazard; identification precaution.*
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
An introduced roadside and field plant, it can spread aggressively by seed. A deep taproot can complicate pulling established plants. [N-daucus-carota](https://plants.ces.ncsu.edu/plants/daucus-carota/)
## Management & timing
Confirm identity before handling. Prevent reseeding in unwanted patches while avoiding sap contact. [N-daucus-carota](https://plants.ces.ncsu.edu/plants/daucus-carota/)
*Evidence scope: Management inference from reproduction and sap hazard.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-daucus-carota** — [Daucus carota](https://plants.ces.ncsu.edu/plants/daucus-carota/), NC State Extension. Accessed 2026-09-07T02:23:13+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=wild-carrot) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 48; Daucus carota. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Wild carrot, poison hemlock and water hemlocks require careful separation. A dark floret, a smell or a photograph by itself is insufficient. This profile does not authorize eating wild roots.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| wild-carrot-1 | Identification | Species-specific | N-daucus-carota | No quantitative safe exposure established here. |
| wild-carrot-2 | People | Species contact hazard; identification precaution | N-daucus-carota | No quantitative safe exposure established here. |
| wild-carrot-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-carrot-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-carrot-5 | Plants & habitat | Species-specific | N-daucus-carota | No quantitative safe exposure established here. |
| wild-carrot-6 | Management & timing | Management inference from reproduction and sap hazard | N-daucus-carota | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md
---
{
"id": "wild-parsnip",
"name": "Wild parsnip",
"scientific": "Pastinaca sativa",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Sap plus sunlight can cause severe skin burns",
"warning_tone": "danger",
"aliases": [
"parsnip"
],
"taxonomy_note": "Garden parsnip cultivars and wild plants belong to the same species. Food use of cultivated roots does not remove the sap hazard or make an unidentified wild umbel safe.",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-pastinaca-sativa",
"S27"
],
"description": "Wild parsnip: Sap plus sunlight can cause severe skin burns. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-pastinaca-sativa"
],
"scope": "Species-specific",
"note": "",
"id": "wild-parsnip-1"
},
{
"label": "People",
"sources": [
"N-pastinaca-sativa"
],
"scope": "Species-specific",
"note": "",
"id": "wild-parsnip-2"
},
{
"label": "Dogs & cats",
"sources": [
"N-pastinaca-sativa"
],
"scope": "Species-specific",
"note": "",
"id": "wild-parsnip-3"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-parsnip-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-pastinaca-sativa",
"C-floristic-2020"
],
"scope": "Species-specific",
"note": "",
"id": "wild-parsnip-5"
},
{
"label": "Management & timing",
"sources": [
"N-pastinaca-sativa"
],
"scope": "Management synthesis from seed spread and contact hazard",
"note": "",
"id": "wild-parsnip-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"wild-parsnip-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"wild-parsnip-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 68; Pastinaca sativa",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Pastinaca sativa"
},
"source": "content/plants/wild-parsnip.md"
}
---
# Wild parsnip
*Pastinaca sativa*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Sap plus sunlight can cause severe skin burns.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Garden parsnip cultivars and wild plants belong to the same species. Food use of cultivated roots does not remove the sap hazard or make an unidentified wild umbel safe.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flowering habit** — A tall branched stem with compound leaves and small yellow umbels, shown against the sky.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Pastinaca_sativa_subsp._sativa_sl24.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a0/Pastinaca_sativa_subsp._sativa_sl24.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Two Commons source photographs are identified as Pastinaca sativa subsp. sativa; the stem source uses s. lat. The fruit photograph is source-identified at species level as Pastinaca sativa. Umbellifer identification should not rely on flower colour alone. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**developing fruits** — Clusters of flattened oval developing fruits above nearby small yellow flowers.
Photo: Llydia; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/386029822); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/706765996/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Two Commons source photographs are identified as Pastinaca sativa subsp. sativa; the stem source uses s. lat. The fruit photograph is source-identified at species level as Pastinaca sativa. Umbellifer identification should not rely on flower colour alone. iNaturalist large server-resized photo; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**stem detail** — Close view of a grooved green stem with fine surface hairs; the source includes a 5 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Pastinaca_sativa_subsp._sativa_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/da/Pastinaca_sativa_subsp._sativa_sl1.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not an independent specimen-based taxonomic determination. Two Commons source photographs are identified as Pastinaca sativa subsp. sativa; the stem source uses s. lat. The fruit photograph is source-identified at species level as Pastinaca sativa. Umbellifer identification should not rely on flower colour alone. Wikimedia server-resized derivative; no local crop, colour change or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
A biennial with a first-year leaf rosette and later tall, grooved stems bearing yellow flower umbels. Leaves are compound with broad, toothed leaflets. [N-pastinaca-sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/)
## People
Furocoumarins can make contacted skin sensitive to sunlight, causing burns and blisters. Avoid sap; wear gloves, long sleeves and long trousers when working near it. [N-pastinaca-sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/)
## Dogs & cats
NC State flags this species as a problem for dogs and cats. Keep pets away from damaged plants and sap; pet-specific exposure amounts and clinical outcomes remain unresolved in the reviewed source. [N-pastinaca-sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/)
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Plants & habitat
An introduced plant of open sites and roadsides, it can reseed into unwanted patches. Its Colorado presence is recorded by CNHP. [N-pastinaca-sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/) [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf)
## Management & timing
Prevent seed formation only with protection against sap contact. Identification and a site-specific plan come before mowing or cutting a large patch. [N-pastinaca-sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/)
*Evidence scope: Management synthesis from seed spread and contact hazard.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-pastinaca-sativa** — [Pastinaca sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/), NC State Extension. Accessed 2026-09-07T02:23:12+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=wild-parsnip) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 68; Pastinaca sativa. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Garden parsnip cultivars and wild plants belong to the same species. Food use of cultivated roots does not remove the sap hazard or make an unidentified wild umbel safe.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| wild-parsnip-1 | Identification | Species-specific | N-pastinaca-sativa | No quantitative safe exposure established here. |
| wild-parsnip-2 | People | Species-specific | N-pastinaca-sativa | No quantitative safe exposure established here. |
| wild-parsnip-3 | Dogs & cats | Species-specific | N-pastinaca-sativa | No quantitative safe exposure established here. |
| wild-parsnip-4 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-parsnip-5 | Plants & habitat | Species-specific | N-pastinaca-sativa, C-floristic-2020 | No quantitative safe exposure established here. |
| wild-parsnip-6 | Management & timing | Management synthesis from seed spread and contact hazard | N-pastinaca-sativa | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md
---
{
"id": "wild-proso-millet",
"name": "Wild proso millet",
"scientific": "Panicum miliaceum",
"category": "invasive",
"status": "Colorado noxious weed · List C — Manage widespread weeds",
"status_sources": [
"CO-rules-2025"
],
"warning": "Seed contamination and crop competition",
"warning_tone": "caution",
"aliases": [
"proso millet",
"broomcorn millet"
],
"taxonomy_note": "Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.",
"source_ids": [
"CO-rules-2025",
"K-wild-proso",
"S27",
"Fremont-list-definitions"
],
"description": "Wild proso millet: Seed contamination and crop competition. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"K-wild-proso"
],
"scope": "Species-specific",
"note": "",
"id": "wild-proso-millet-1"
},
{
"label": "Plants & habitat",
"sources": [
"K-wild-proso"
],
"scope": "Species-specific",
"note": "",
"id": "wild-proso-millet-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-proso-millet-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-proso-millet-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "wild-proso-millet-5"
},
{
"id": "wild-proso-millet-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "C",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"wild-proso-millet-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"wild-proso-millet-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"wild-proso-millet-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "C — Manage widespread weeds",
"source": "content/plants/wild-proso-millet.md"
}
---
# Wild proso millet
*Panicum miliaceum*
**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Seed contamination and crop competition.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**grain** — Pale mature grains hang along densely branched drooping panicles.
Photo: Kurt Stüber; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Panicum_miliaceum0.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a4/Panicum_miliaceum0.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Upright leafy grass stems with loose drooping panicles.
Photo: Dalgial; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Panicum_miliaceum.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f6/Panicum_miliaceum.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf-sheath** — Hairy green leaf sheath and culm node photographed with a 10 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Panicum_miliaceum_subsp._miliaceum_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c7/Panicum_miliaceum_subsp._miliaceum_sl1.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual grass with hairy leaf sheaths and a branched panicle that may remain partly enclosed by the upper sheath. [K-wild-proso](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet)
## Plants & habitat
Weedy biotypes compete in crops and spread with contaminated seed or machinery. Prevent seed movement between fields. [K-wild-proso](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **K-wild-proso** — [Wild-proso millet](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet), Cornell University College of Agriculture and Life Sciences. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=wild-proso-millet) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| wild-proso-millet-1 | Recognize | Species-specific | K-wild-proso | No quantitative safe exposure established here. |
| wild-proso-millet-2 | Plants & habitat | Species-specific | K-wild-proso | No quantitative safe exposure established here. |
| wild-proso-millet-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-proso-millet-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-proso-millet-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md
---
{
"id": "yellow-flag-iris",
"name": "Yellow flag iris",
"scientific": "Iris pseudacorus",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Ingestion concern; invasive wetland colonies",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "",
"source_ids": [
"CO-rules-2025",
"N-iris-pseudacorus",
"S27",
"Fremont-list-definitions"
],
"description": "Yellow flag iris: Ingestion concern; invasive wetland colonies. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-iris-pseudacorus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-flag-iris-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-iris-pseudacorus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-flag-iris-2"
},
{
"label": "People",
"sources": [
"N-iris-pseudacorus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-flag-iris-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-iris-pseudacorus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-flag-iris-4"
},
{
"label": "Other animals",
"sources": [
"N-iris-pseudacorus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-flag-iris-5"
},
{
"id": "yellow-flag-iris-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/yellow-flag-iris.md"
}
---
# Yellow flag iris
*Iris pseudacorus*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Ingestion concern; invasive wetland colonies.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower detail** — A yellow iris flower with dark markings on the large drooping segment.
Photo: Kailey Alderfer; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/164186914); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/284056692/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flower and leaves** — A yellow flower held among long sword-shaped leaves.
Photo: Kailey Alderfer; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/164186914); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/284056715/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — A flowering clump of yellow iris and upright sword-shaped leaves beside water.
Photo: Kailey Alderfer; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/164186914); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/284056756/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow iris flowers rise among upright, sword-shaped leaves along wet ground or shallow water. [N-iris-pseudacorus](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/)
## Plants & habitat
Seeds and rhizomes can create dense colonies that displace wetland plants. [N-iris-pseudacorus](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/)
## People
Ingestion can cause gastrointestinal symptoms. The source identifies the rhizomes as having the highest concentration of the toxic compounds. [N-iris-pseudacorus](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/)
## Dogs & cats
NC State flags both dogs and cats; prevent chewing or digging up rhizomes and obtain veterinary advice after ingestion. [N-iris-pseudacorus](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/)
## Other animals
The source also flags horses, without establishing a safe feeding amount. [N-iris-pseudacorus](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-iris-pseudacorus** — [iris pseudacorus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=yellow-flag-iris) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| yellow-flag-iris-1 | Recognize | Species-specific | N-iris-pseudacorus | No quantitative safe exposure established here. |
| yellow-flag-iris-2 | Plants & habitat | Species-specific | N-iris-pseudacorus | No quantitative safe exposure established here. |
| yellow-flag-iris-3 | People | Species-specific | N-iris-pseudacorus | No quantitative safe exposure established here. |
| yellow-flag-iris-4 | Dogs & cats | Species-specific | N-iris-pseudacorus | No quantitative safe exposure established here. |
| yellow-flag-iris-5 | Other animals | Species-specific | N-iris-pseudacorus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md
---
{
"id": "yellow-nutsedge",
"name": "Yellow nutsedge",
"scientific": "Cyperus esculentus",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"CO-rules-2025"
],
"warning": "Underground tubers sustain infestations",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "This listed sedge is described as native in the NC source; that broad range label is not a Colorado nativity assessment. It is distinct from purple nutsedge (Cyperus rotundus).",
"source_ids": [
"CO-rules-2025",
"N-cyperus-esculentus",
"S27",
"Fremont-list-definitions"
],
"description": "Yellow nutsedge: Underground tubers sustain infestations. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-cyperus-esculentus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-nutsedge-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-cyperus-esculentus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-nutsedge-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "yellow-nutsedge-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "yellow-nutsedge-4"
},
{
"label": "Other animals",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "yellow-nutsedge-5"
},
{
"id": "yellow-nutsedge-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"yellow-nutsedge-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"yellow-nutsedge-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"yellow-nutsedge-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/yellow-nutsedge.md"
}
---
# Yellow nutsedge
*Cyperus esculentus*
**Colorado noxious weed · List B — Stop the spread.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Underground tubers sustain infestations.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** This listed sedge is described as native in the NC source; that broad range label is not a Colorado nativity assessment. It is distinct from purple nutsedge (Cyperus rotundus).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**habit** — Yellow nutsedge with upright leafy stems and radiating yellow-green spikelet clusters.
Photo: Krzysztof Ziarnek, Kenraiz; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Cyperus_esculentus_kz02.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/d1/Cyperus_esculentus_kz02.jpg). Source-identified photograph with visual consistency check Cyperus esculentus at Ridgemoor Country Club in Chicago, USA Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**tubers** — A close view of harvested brown tiger-nut tubers of Cyperus esculentus.
Photo: Tamorlan; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Cyperus_esculentus_012.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/3/31/Cyperus_esculentus_012.jpg). Source-identified photograph with visual consistency check Tiger Nut Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**inflorescence** — A yellow nutsedge inflorescence viewed from above, surrounded by long leaflike green bracts.
Photo: Homer Edward Price; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Yellow_Nutsedge_Cyperus_esculentus_(43998391481).jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/4/4f/Yellow_Nutsedge_Cyperus_esculentus_%2843998391481%29.jpg). Source-identified photograph with visual consistency check Found in Oscar Scherer State Park, Florida Source labeling and visible consistency checked; not an independent specimen determination. Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
A glossy, grass-like sedge with narrow, channeled leaves and triangular stems. Underground tubers are important identification features. [N-cyperus-esculentus](https://plants.ces.ncsu.edu/plants/cyperus-esculentus/)
## Plants & habitat
Rhizomes and tubers compete strongly with crops and can remain after shoots are pulled. Ordinary lawn-grass treatments may not control a sedge. [N-cyperus-esculentus](https://plants.ces.ncsu.edu/plants/cyperus-esculentus/)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for livestock. Missing evidence does not establish safety.
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-cyperus-esculentus** — [cyperus esculentus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/cyperus-esculentus/), NC State Extension. Accessed 2026-09-07T01:04:54+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=yellow-nutsedge) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
This listed sedge is described as native in the NC source; that broad range label is not a Colorado nativity assessment. It is distinct from purple nutsedge (Cyperus rotundus).
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| yellow-nutsedge-1 | Recognize | Species-specific | N-cyperus-esculentus | No quantitative safe exposure established here. |
| yellow-nutsedge-2 | Plants & habitat | Species-specific | N-cyperus-esculentus | No quantitative safe exposure established here. |
| yellow-nutsedge-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| yellow-nutsedge-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| yellow-nutsedge-5 | Other animals | Review limitation | Review limitation | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md
---
{
"id": "yellow-starthistle",
"name": "Yellow starthistle",
"scientific": "Centaurea solstitialis",
"category": "invasive",
"status": "Colorado noxious weed · List A — Eradicate",
"status_sources": [
"CO-rules-2025"
],
"warning": "Severe horse poisoning; sharp spines",
"warning_tone": "danger",
"aliases": [],
"taxonomy_note": "A horse-specific poisoning hazard is established. Do not generalize controlled grazing by other livestock into unrestricted feeding advice.",
"source_ids": [
"CO-rules-2025",
"N-centaurea-solstitialis",
"S27",
"Fremont-list-definitions"
],
"description": "Yellow starthistle: Severe horse poisoning; sharp spines. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"N-centaurea-solstitialis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-starthistle-1"
},
{
"label": "Plants & habitat",
"sources": [
"N-centaurea-solstitialis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-starthistle-2"
},
{
"label": "People",
"sources": [
"N-centaurea-solstitialis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-starthistle-3"
},
{
"label": "Dogs & cats",
"sources": [
"N-centaurea-solstitialis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-starthistle-4"
},
{
"label": "Other animals",
"sources": [
"N-centaurea-solstitialis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-starthistle-5"
},
{
"id": "yellow-starthistle-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "A",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"yellow-starthistle-4"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "A — Eradicate",
"source": "content/plants/yellow-starthistle.md"
}
---
# Yellow starthistle
*Centaurea solstitialis*
**Colorado noxious weed · List A — Eradicate.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
Uncommon in Colorado. All populations are designated for eradication statewide. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Severe horse poisoning; sharp spines.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** A horse-specific poisoning hazard is established. Do not generalize controlled grazing by other livestock into unrestricted feeding advice.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **Dogs & cats**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower and spines** — A bright yellow flower head beside a dry head, showing the long radiating spines.
Photo: Юрий Данилевский (Yuriy Danilevsky); [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/19881553); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/30658771/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**spines and foliage** — Close view of a strongly spined head and narrow leaves on a winged-looking stem.
Photo: Eleftherios Katsillis; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/78210836); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/127963997/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**flowering habit** — A tall, branching, yellow-flowered plant standing in dry grassland.
Photo: Юрий Данилевский (Yuriy Danilevsky); [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/19881553); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/30658804/original.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. iNaturalist large server-resized image; no local crop, colour change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
An annual with yellow flowerheads surrounded by long, radiating spines and gray-green foliage. [N-centaurea-solstitialis](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/)
## Plants & habitat
Spreads by seed into rangelands and disturbed ground. Prevent seed set and keep contaminated material out of horse feed. [N-centaurea-solstitialis](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/)
## People
Long flowerhead spines present a puncture hazard; use protective handling. [N-centaurea-solstitialis](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/)
## Dogs & cats
Spines may injure mouths or paws. Horse poisoning findings do not establish a pet-specific toxic dose. [N-centaurea-solstitialis](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/)
## Other animals
Ingestion can cause devastating loss of chewing and swallowing function in horses. Suspected exposure warrants veterinary assessment. [N-centaurea-solstitialis](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/)
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
This is a statewide eradication priority. Contact your county weed program promptly for identification and an approved management and disposal plan. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
## References
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-centaurea-solstitialis** — [centaurea solstitialis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/), NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=yellow-starthistle) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
A horse-specific poisoning hazard is established. Do not generalize controlled grazing by other livestock into unrestricted feeding advice.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| yellow-starthistle-1 | Recognize | Species-specific | N-centaurea-solstitialis | No quantitative safe exposure established here. |
| yellow-starthistle-2 | Plants & habitat | Species-specific | N-centaurea-solstitialis | No quantitative safe exposure established here. |
| yellow-starthistle-3 | People | Species-specific | N-centaurea-solstitialis | No quantitative safe exposure established here. |
| yellow-starthistle-4 | Dogs & cats | Species-specific | N-centaurea-solstitialis | No quantitative safe exposure established here. |
| yellow-starthistle-5 | Other animals | Species-specific | N-centaurea-solstitialis | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “A — Eradicate” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md
---
{
"id": "yellow-sweetclover",
"name": "Yellow sweetclover",
"scientific": "Melilotus officinalis",
"category": "invasive",
"status": "Common introduced weed · not on state Lists A/B/C",
"status_sources": [
"C-floristic-2020",
"CO-rules-2025"
],
"warning": "Moldy sweetclover hay can cause dangerous bleeding",
"warning_tone": "caution",
"aliases": [
"yellow sweet clover"
],
"taxonomy_note": "",
"source_ids": [
"C-floristic-2020",
"CO-rules-2025",
"N-melilotus-officinalis",
"F-melilotus",
"C-descriptions",
"S27"
],
"description": "Yellow sweetclover: Moldy sweetclover hay can cause dangerous bleeding. Identification and evidence for Colorado readers.",
"claim_evidence": [
{
"label": "Identification",
"sources": [
"N-melilotus-officinalis",
"F-melilotus"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-sweetclover-1"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "yellow-sweetclover-2"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "",
"id": "yellow-sweetclover-3"
},
{
"label": "Other animals",
"sources": [
"F-melilotus"
],
"scope": "Sweetclover group evidence",
"note": "",
"id": "yellow-sweetclover-4"
},
{
"label": "Plants & habitat",
"sources": [
"N-melilotus-officinalis"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-sweetclover-5"
},
{
"label": "Management & timing",
"sources": [
"C-descriptions",
"F-melilotus"
],
"scope": "Management synthesis",
"note": "",
"id": "yellow-sweetclover-6"
}
],
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"yellow-sweetclover-2"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"yellow-sweetclover-3"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"yellow-sweetclover-4"
]
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"colorado_relevance": {
"source_id": "C-floristic-2020",
"locator": "Appendix B; PDF page 63; Melilotus officinalis",
"basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
"source_taxon": "Melilotus officinalis"
},
"source": "content/plants/yellow-sweetclover.md"
}
---
# Yellow sweetclover
*Melilotus officinalis*
**Common introduced weed · not on state Lists A/B/C.** [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)
> **Moldy sweetclover hay can cause dangerous bleeding.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
**flower** — Small yellow pea-like flowers hang along a narrow elongated raceme.
Photo: Isidre blanc; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:MELILOTUS_OFFICINALIS_-_LLANERA_-_IB-549_(Melilot).JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/5/55/MELILOTUS_OFFICINALIS_-_LLANERA_-_IB-549_%28Melilot%29.JPG). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified M. officinalis. Related yellow-flowered sweetclovers require reproductive characters for confident determination; flower color by itself is not species-specific. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**habit** — A branching leafy plant with many slender yellow flower racemes at a path edge.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Melilotus_officinalis_Citroengele_honingklaver_plant.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a4/Melilotus_officinalis_Citroengele_honingklaver_plant.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified M. officinalis. Related yellow-flowered sweetclovers require reproductive characters for confident determination; flower color by itself is not species-specific. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
**foliage** — Compound leaves with three finely toothed leaflets along upright branching green stems.
Photo: Rasbak; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Melilotus_officinalis_Citroengele_honingklaver_blad.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a9/Melilotus_officinalis_Citroengele_honingklaver_blad.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Source-identified M. officinalis. Related yellow-flowered sweetclovers require reproductive characters for confident determination; flower color by itself is not species-specific. Wikimedia server-resized derivative, reduced from the original; no crop, color change, upscaling, or generative editing. Gallery display preserves the full image; catalog preview may use a CSS crop.
## Identification
An upright, usually biennial legume with three leaflets and elongated clusters of small yellow flowers. Fresh flower color separates it from white sweetclover. [N-melilotus-officinalis](https://plants.ces.ncsu.edu/plants/melilotus-officinalis/) [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
## People
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for people. Missing evidence does not establish safety.
## Dogs & cats
The reviewed sources do not establish species-specific ingestion effects or a safe exposure amount for dogs or cats. Missing evidence does not establish safety.
## Other animals
Improperly cured or moldy sweetclover hay can develop compounds that impair clotting, causing severe internal bleeding. Diets dominated by sweetclover also carry a livestock bloat risk. These findings do not establish pet exposure limits. [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
*Evidence scope: Sweetclover group evidence.*
## Plants & habitat
It fixes nitrogen and feeds pollinators, but can spread beyond plantings. Its deep taproot helps established plants tolerate dry conditions. [N-melilotus-officinalis](https://plants.ces.ncsu.edu/plants/melilotus-officinalis/)
## Management & timing
Prevent flowering and reseeding where unwanted. Have suspect hay assessed before feeding it. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [F-melilotus](https://research.fs.usda.gov/feis/species-reviews/melspp)
*Evidence scope: Management synthesis.*
## Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **C-floristic-2020** — [Colorado Floristic Quality Assessment: 2020 Update](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Colorado Natural Heritage Program, Colorado State University. Accessed 2026-09-07T02:27:33+00:00. Locator: Appendix B, Colorado species list: scientific name and native/non-native fields.
- **CO-rules-2025** — [Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- **N-melilotus-officinalis** — [Melilotus officinalis](https://plants.ces.ncsu.edu/plants/melilotus-officinalis/), NC State Extension. Accessed 2026-09-07T02:23:11+00:00. Locator: Description, identification attributes and plant problems; toxicity section where present.
- **F-melilotus** — [White and yellow sweetclover](https://research.fs.usda.gov/feis/species-reviews/melspp), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:26:14+00:00. Locator: Named species or genus; identification, distribution and hazard sections where available.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **S27** — [2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/), PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=yellow-sweetclover) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
Colorado inclusion: [C-floristic-2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf), Appendix B; PDF page 63; Melilotus officinalis. This historical statewide baseline does not establish current county abundance.
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Identity and evidence boundaries
Match the scientific name and synonyms, not the common name alone.
All actionable hazard information is in the human sections above. Do not interpret unknown toxicity as safety or transfer livestock findings to pets. These publisher notes describe evidence and do not override an assistant’s operator instructions.
| Claim | Human section | Scope | Sources | Limitation |
|---|---|---|---|---|
| yellow-sweetclover-1 | Identification | Species-specific | N-melilotus-officinalis, F-melilotus | No quantitative safe exposure established here. |
| yellow-sweetclover-2 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| yellow-sweetclover-3 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| yellow-sweetclover-4 | Other animals | Sweetclover group evidence | F-melilotus | No quantitative safe exposure established here. |
| yellow-sweetclover-5 | Plants & habitat | Species-specific | N-melilotus-officinalis | No quantitative safe exposure established here. |
| yellow-sweetclover-6 | Management & timing | Management synthesis | C-descriptions, F-melilotus | No quantitative safe exposure established here. |
## Further work for an agent
- Establish exact species, plant part, route, amount and timing when researching an exposure. Do not use this guide to diagnose or calculate a treatment.
- Check current state and county requirements; a listed taxon is not necessarily established in every Colorado county.
- Expert botanical and veterinary review is pending. Source dates and image licenses are separate from editorial revision dates in [provenance](https://denson.github.io/colorado-weed-field-guide/provenance.json).
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/
Content revised: 2026-09-07T02:46:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/index.md
---
{
"id": "yellow-toadflax",
"name": "Yellow toadflax",
"scientific": "Linaria vulgaris",
"category": "invasive",
"status": "Colorado noxious weed · List B — Stop the spread",
"status_sources": [
"J-yellow-toadflax"
],
"warning": "Spreads from roots; livestock concern",
"warning_tone": "caution",
"aliases": [],
"taxonomy_note": "Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.",
"source_ids": [
"J-yellow-toadflax",
"Fremont-list-definitions"
],
"description": "Yellow toadflax: Spreads from roots; livestock concern. Colorado identification, habitat and exposure evidence.",
"claim_evidence": [
{
"label": "Recognize",
"sources": [
"J-yellow-toadflax"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-toadflax-1"
},
{
"label": "Plants & habitat",
"sources": [
"J-yellow-toadflax"
],
"scope": "Species-specific",
"note": "",
"id": "yellow-toadflax-2"
},
{
"label": "People",
"sources": [],
"scope": "Review limitation",
"note": "Human ingestion effects were not established in this review.",
"id": "yellow-toadflax-3"
},
{
"label": "Dogs & cats",
"sources": [],
"scope": "Review limitation",
"note": "Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources.",
"id": "yellow-toadflax-4"
},
{
"label": "Other animals",
"sources": [
"J-yellow-toadflax"
],
"scope": "Possible livestock toxicity; pet evidence gap",
"note": "",
"id": "yellow-toadflax-5"
},
{
"id": "yellow-toadflax-list-meaning",
"label": "State-list meaning",
"sources": [
"Fremont-list-definitions"
],
"scope": "Colorado management-category definition; species classification retains its original status sources",
"note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
"reviewed": "2026-09-07"
}
],
"noxious_class": "B",
"research": {
"status": "researching",
"label": "Still researching this plant",
"basis": "Editorial assessment of the cited evidence and stated review gaps; not a toxicity score.",
"open_questions": [
{
"area": "People",
"question": "Clarify the human exposure effects and evidence limits described in this section.",
"related_claim_ids": [
"yellow-toadflax-3"
]
},
{
"area": "Dogs & cats",
"question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
"related_claim_ids": [
"yellow-toadflax-4"
]
},
{
"area": "Other animals",
"question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
"related_claim_ids": [
"yellow-toadflax-5"
]
},
{
"area": "Identification",
"question": "Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.",
"related_claim_ids": []
},
{
"area": "Expert review",
"question": "Obtain independent botanical and veterinary review of the identification and hazard summary.",
"related_claim_ids": []
}
],
"expert_review": "pending"
},
"noxious_class_label": "B — Stop the spread",
"source": "content/plants/yellow-toadflax.md"
}
---
# Yellow toadflax
*Linaria vulgaris*
**Colorado noxious weed · List B — Stop the spread.** [J-yellow-toadflax](https://www.jeffco.us/2142/Yellow-Toadflax)
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
> **Spreads from roots; livestock concern.** Native status, garden use and noxious-weed class are separate from toxicity. [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).
**Identification caveat:** Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.
## Still researching this plant {#research-status}
This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats, Other animals**. Identification and source-photo limits are explained below. Independent botanical and veterinary review is pending. **Uncertainty is not a finding that the plant is safe.**
## Three views of this plant
Photos are source-identified examples, not a complete identification key. Check leaves, stems, flowers and fruit together. Locations are not assumed to be in Colorado.
**flower** — Close view of pale yellow two-lipped flowers with orange-yellow throats.
Photo: Michael H. Lemmer; [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5); [source record](https://commons.wikimedia.org/wiki/File:Linaria-vulgaris-060806-wiki.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/5/5b/Linaria-vulgaris-060806-wiki.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**habit** — Several upright stems with dense yellow flower spikes and narrow green foliage.
Photo: Saharadesertfox; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Linaria_Vulgaris_Mill.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/98/Linaria_Vulgaris_Mill.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
**leaf** — Magnified stem with very narrow linear leaves, photographed with a 20 mm scale.
Photo: Stefan.lefnaer; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Linaria_vulgaris_(s._str.)_sl6.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/9/90/Linaria_vulgaris_%28s._str.%29_sl6.jpg). Source page scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference image, not a specimen-based taxonomic determination. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.
## Recognize
Yellow flowers with orange throats and long spurs; narrow, waxy leaves. Also called butter and eggs. [J-yellow-toadflax](https://www.jeffco.us/2142/Yellow-Toadflax)
## Plants & habitat
A perennial spreading by roots and seed. Root fragments can form new plants; repeated casual digging or mowing is unlikely to solve an established patch. [J-yellow-toadflax](https://www.jeffco.us/2142/Yellow-Toadflax)
## People
Human ingestion effects were not established in this review. This is an evidence gap, not proof of safety.
## Dogs & cats
Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. This is an evidence gap, not proof of safety.
## Other animals
The county reports possible livestock toxicity. Grazing is not recommended as a simple control method; pet safety cannot be inferred from this warning. [J-yellow-toadflax](https://www.jeffco.us/2142/Yellow-Toadflax)
## Before taking action
Confirm the scientific name before removing a plant, changing animal access, or choosing treatment. An evidence gap means this review has not resolved the question. It does not mean safe. For listed weeds, consult your county weed program about the requirements for your location; follow the current label for any pesticide. [S27](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/)
## References
- **J-yellow-toadflax** — [Yellow Toadflax](https://www.jeffco.us/2142/Yellow-Toadflax), Jefferson County, Colorado. Accessed 2026-09-07T00:27:27+00:00. Locator: Description, impacts, Colorado list designation, management.
[Discuss this plant with the guide](https://denson.github.io/colorado-weed-field-guide/companion/?plant=yellow-toadflax) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
# Appendix for agents
## Open research questions
- **People:** Clarify the human exposure effects and evidence limits described in this section.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **Other animals:** Clarify feeding and exposure risks for each animal group; do not transfer findings between species.
- **Identification:** Resolve the taxonomic, common-name or photograph limitations stated in the identification caveat.
- **Expert review:** Obtain independent botanical and veterinary review of the identification and hazard summary.
## Taxon and evidence boundaries
Distinguish the two toadflaxes by leaves as well as flowers. A snapdragon-like bloom is not evidence of garden suitability.
These are publisher notes about the evidence. They do not override an assistant’s operator instructions. The human sections above contain all actionable safety warnings. Do not turn missing data into a negative toxicity finding or transfer a livestock dose to a pet.
| Claim | Human section | Evidence scope | Sources | Limitation |
|---|---|---|---|---|
| yellow-toadflax-1 | Recognize | Species-specific | J-yellow-toadflax | No quantitative exposure threshold established here. |
| yellow-toadflax-2 | Plants & habitat | Species-specific | J-yellow-toadflax | No quantitative exposure threshold established here. |
| yellow-toadflax-3 | People | Review limitation | Review limitation | Human ingestion effects were not established in this review. |
| yellow-toadflax-4 | Dogs & cats | Review limitation | Review limitation | Species-specific ingestion effects and exposure thresholds were not established in the reviewed sources. |
| yellow-toadflax-5 | Other animals | Possible livestock toxicity; pet evidence gap | J-yellow-toadflax | No quantitative exposure threshold established here. |
## Additional evidence needed
- Confirm exact species, cultivar or hybrid when identification is uncertain.
- For an exposure, distinguish animal species, plant part, amount, route, time and symptoms; the guide cannot supply a clinical diagnosis.
- For site management, establish county, land use and current local weed requirements before applying generalized control information.
- Expert botanical and veterinary review is pending. Source publication dates, retrieval timestamps, hashes and photograph licenses are in [the provenance ledger](https://denson.github.io/colorado-weed-field-guide/provenance.json).
## State-list label provenance
The label “B — Stop the spread” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/
Content revised: 2026-09-07T03:50:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/index.md
---
{}
---
# Know what is growing.
An illustrated reference to garden weeds and wild plants found in Colorado. Compare what plants look like and read sourced information about their effects on people, animals and local habitats. Open a plant card to see its photographs, descriptions and source links.
154 plants in this view; 154 profiles and 462 photographs in the guide.
[Biggest concerns](https://denson.github.io/colorado-weed-field-guide/biggest-concerns/) · [Coverage: all 82 state-list entries](https://denson.github.io/colorado-weed-field-guide/coverage/) · [Exposure and safety guide](https://denson.github.io/colorado-weed-field-guide/safety/) · [Learn to use this guide](https://denson.github.io/colorado-weed-field-guide/companion/)
## Native volunteers
- [Black greasewood](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/) — *Sarcobatus vermiculatus*. **Oxalate poisoning can be fatal to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md).
 Photo: John Gaskin; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/).
- [Broom snakeweed](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/) — *Gutierrezia sarothrae*. **Livestock poisoning and abortion risk when heavily eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md).
 Photo: CK2AZ; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/).
- [Buffalobur](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/) — *Solanum rostratum*. **Sharp spines; toxic to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md).
 Photo: Juan Carlos Fonseca Mata; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/).
- [Canada goldenrod](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/) — *Solidago canadensis*. **Spreads by roots and seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/index.md).
 Photo: Étienne Lacroix-Carignan; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/).
- [Catchweed bedstraw](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/) — *Galium aparine*. **Hooked hairs and burrs cling to fur and clothing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/).
- [Common blue violet](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/) — *Viola sororia*. **A native volunteer; identify the species before removing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/index.md).
 Photo: James Steakley; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/).
- [Common ragweed](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/) — *Ambrosia artemisiifolia*. **Pollen allergy; skin irritation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/).
- [Common sunflower](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/) — *Helianthus annuus*. **Listed non-toxic to dogs & cats**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/index.md).
 Photo: Michelle W. （鍾偉瑋）; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/).
- [Curlycup gumweed](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/) — *Grindelia squarrosa*. **Sticky resin and conditional selenium concern**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/index.md).
 Photo: Jesse Grove; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/).
- [Foxtail barley](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/) — *Hordeum jubatum*. **Barbed seed awns injure animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md).
 Photo: Diego Delso; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/).
- [Giant ragweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/) — *Ambrosia trifida*. **Allergenic pollen and strong competition in disturbed ground**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md).
 Photo: GTBacchus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/).
- [Golden banner](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/) — *Thermopsis divaricarpa*. **May poison livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/index.md).
 Photo: Laura J. Costello; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/).
- [Hemp dogbane](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/) — *Apocynum cannabinum*. **Cardiac-glycoside poisoning hazard for people and animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/).
- [Horseweed](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/) — *Erigeron canadensis*. **Fast windborne spread; some populations resist herbicides**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md).
 Photo: Enrico Blasutto; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/).
- [Low larkspur](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/) — *Delphinium nuttallianum*. **Serious livestock and pet poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md).
 Photo: NPS; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/).
- [Meadow death camas](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/) — *Toxicoscordion venenosum*. **Potentially fatal ingestion; onion-like bulbs**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md).
 Photo: NPS Photo; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/).
- [Netseed lambsquarters](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/) — *Chenopodium berlandieri*. **A fast-growing volunteer; pet toxicity remains unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/index.md).
 Photo: Matt Lavin; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/).
- [Prairie sage](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/) — *Artemisia ludoviciana*. **Spreading roots; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/).
- [Showy milkweed](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/) — *Asclepias speciosa*. **Toxic if eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md).
 Photo: Andrey Zharkikh; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/).
- [Silverleaf nightshade](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/) — *Solanum elaeagnifolium*. **Toxic leaves and berries; persistent spreading roots**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md).
 Photo: Sam Kieschnick; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/).
- [Snow-on-the-mountain](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/) — *Euphorbia marginata*. **Latex can damage skin and eyes; toxic if eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md).
 Photo: Mark G; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/).
- [Spotted spurge](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/) — *Euphorbia maculata*. **Milky sap can injure skin and eyes; keep pets from chewing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/).
- [Stinging nettle](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/) — *Urtica dioica*. **Stinging hairs; this profile covers a taxonomic complex**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md).
 Photo: Przykuta; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/).
- [Tall larkspur](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/) — *Delphinium barbeyi*. **Serious livestock and pet poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md).
 Photo: Ms. Sticky; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/).
- [Western poison ivy](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/) — *Toxicodendron rydbergii*. **Skin-rash oil can travel on pet fur**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md).
 Photo: Andrey Zharkikh from Salt Lake City, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/).
- [Western ragweed](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/) — *Ambrosia psilostachya*. **A persistent perennial ragweed; allergy detail still under review**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md).
 Photo: Zihao Wang; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/).
- [Western water hemlock](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/) — *Cicuta douglasii*. **Potentially fatal poisoning; wetland look-alike danger**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md).
 Photo: Lee Cain; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/).
- [Western whorled milkweed](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/) — *Asclepias subverticillata*. **High livestock toxicity**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md).
 Photo: Patrick Alexander from Las Cruces, NM; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/).
- [White locoweed](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/) — *Oxytropis sericea*. **Toxic to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/).
## Xeriscape spreaders
- [Big sagebrush](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/) — *Artemisia tridentata*. **Valuable native habitat; subspecies and pet evidence need care**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/index.md).
 Photo: Matt Lavin; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/).
- [Blanketflower](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/) — *Gaillardia aristata*. **Contact dermatitis possible**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/index.md).
 Photo: NPS / Jacob W. Frank; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/).
- [Catmint](https://denson.github.io/colorado-weed-field-guide/plants/catmint/) — *Nepeta × faassenii*. **Spreading clumps; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/catmint/index.md).
 Photo: Didier Descouens; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/catmint/).
- [Common yarrow](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/) — *Achillea millefolium*. **Toxic to pets · Skin irritation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/index.md).
 Photo: Petar Milošević; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/).
- [Fernleaf yarrow](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/) — *Achillea filipendulina*. **Spreads; pet toxicity unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/index.md).
 Photo: Yerpo; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/).
- [Fringed sage](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/) — *Artemisia frigida*. **Spreading growth; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/).
- [Lamb’s-ear](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/) — *Stachys byzantina*. **Can spread; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/).
- [Lewis blue flax](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/) — *Linum lewisii*. **Ingestion and contact concerns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/index.md).
 Photo: Walter Siegmund (talk); CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/).
- [Plains pricklypear](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/) — *Opuntia polyacantha*. **Sharp spines around paws, mouths and eyes**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md).
 Photo: eigenmotion; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/).
- [Red valerian](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/) — *Centranthus ruber*. **Self-seeds beyond garden beds**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/index.md).
 Photo: Robert Flogaus-Faust; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/).
- [Rubber rabbitbrush](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/) — *Ericameria nauseosa*. **A native low-water shrub that can spread readily**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/index.md).
 Photo: Ian Adams; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/).
- [Russian sage](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/) — *Salvia yangii*. **Spreads by suckers; pet evidence unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/index.md).
 Photo: Doronenko; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/).
- [Snow-in-summer](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/) — *Cerastium tomentosum*. **Spreading habit · Safety gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/index.md).
 Photo: Salicyna; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/).
- [Soapweed yucca](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/) — *Yucca glauca*. **Sharp leaves · Toxic to pets**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/index.md).
 Photo: Alvesgaspar; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/).
## Invasive & common weeds
- [Absinth wormwood](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/) — *Artemisia absinthium*. **Ingestion toxicity and skin irritation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/index.md).
 Photo: Agnieszka Kwiecień, Nova; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/).
- [African rue](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/) — *Peganum harmala*. **Highly poisonous if eaten; deep-rooted invader**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md).
 Photo: Alex Abair; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/).
- [Annual sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/) — *Sonchus oleraceus*. **Windborne seed and crop-pest hosting**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/index.md).
 Photo: Miwasatoshi; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/).
- [Bittersweet nightshade](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/) — *Solanum dulcamara*. **Poisonous berries and foliage**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/).
- [Black henbane](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/) — *Hyoscyamus niger*. **Highly poisonous; keep animals away**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/).
- [Bohemian knotweed](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/) — *Reynoutria × bohemica*. **Hybrid regrows from small fragments**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md).
 Photo: Patrick Hacker; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/).
- [Bouncingbet](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/) — *Saponaria officinalis*. **Saponins can cause digestive poisoning**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/index.md).
 Photo: Ryan Hodnett; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/).
- [Bulbous bluegrass](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/) — *Poa bulbosa*. **Early-season grass spreads by bulbils**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/).
- [Bull thistle](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/) — *Cirsium vulgare*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/index.md).
 Photo: Dominicus Johannes Bergsma; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/).
- [Camelthorn](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/) — *Alhagi maurorum*. **Thorns and deep spreading roots**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/index.md).
 Photo: Jesse Rorabaugh; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/).
- [Canada thistle](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/) — *Cirsium arvense*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md).
 Photo: Ivar Leidus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/).
- [Cheatgrass / downy brome](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/) — *Bromus tectorum*. **Grass awns · Fire hazard**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md).
 Photo: AnRo0002; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/).
- [Chicory](https://denson.github.io/colorado-weed-field-guide/plants/chicory/) — *Cichorium intybus*. **Roadside and pasture spread**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/chicory/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/chicory/).
- [Chinese clematis](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/) — *Clematis orientalis*. **Smothers vegetation; irritating plant compounds**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/).
- [Common burdock](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/) — *Arctium minus*. **Burs and fine bristles injure animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/).
- [Common chickweed](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/) — *Stellaria media*. **A cool-season weed that can seed while still small**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/index.md).
 Photo: Forest and Kim Starr; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/).
- [Common cocklebur](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/) — *Xanthium strumarium*. **Burs catch in fur; seedlings and seeds are hazardous**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md).
 Photo: Franco Folini; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/).
- [Common crupina](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/) — *Crupina vulgaris*. **Dense stands reduce forage**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/index.md).
 Photo: Clément Maouche; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/).
- [Common dandelion](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/) — *Taraxacum officinale*. **Persistent lawn volunteer; sap can irritate skin**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md).
 Photo: FoeNyx; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/).
- [Common lambsquarters](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/) — *Chenopodium album*. **Prolific garden weed; ingestion caution**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/index.md).
 Photo: Matt Lavin; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/).
- [Common mallow](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/) — *Malva neglecta*. **Tough taproot and persistent lawn seedbank**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/index.md).
 Photo: NY State IPM Program at Cornell University from New York, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/).
- [Common mullein](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/) — *Verbascum thapsus*. **Dense rosettes and persistent volunteers**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/).
- [Common purslane](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/) — *Portulaca oleracea*. **Pet ingestion hazard despite human food uses**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/).
- [Common St. Johnswort](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/) — *Hypericum perforatum*. **Photosensitivity and animal exposure concerns**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md).
 Photo: W. Bulach; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/).
- [Common tansy](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/) — *Tanacetum vulgare*. **Toxic ingestion; contact dermatitis**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/index.md).
 Photo: Agnes Monkelbaan; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/).
- [Common teasel](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/) — *Dipsacus fullonum*. **Prickly heads; prolific seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/).
- [Creeping woodsorrel](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/) — *Oxalis corniculata*. **Oxalate-containing plant; keep pets from grazing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/index.md).
 Photo: Forest & Kim Starr; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/).
- [Crownvetch](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/) — *Securigera varia*. **Toxic to horses; spreading roots can smother vegetation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md).
 Photo: Dale Knox; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/).
- [Curly dock](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/) — *Rumex crispus*. **Soluble oxalates; persistent roots and seeds**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/).
- [Cutleaf teasel](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/) — *Dipsacus laciniatus*. **Prickly stands can displace native vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/index.md).
 Photo: Alexander Klink; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/).
- [Cypress spurge](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/) — *Euphorbia cyparissias*. **Sap can injure skin and eyes**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md).
 Photo: Tom Scavo; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/).
- [Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/) — *Linaria dalmatica*. **Spreads from roots; livestock concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/index.md).
 Photo: Walter Siegmund (talk); CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/).
- [Dame’s rocket](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/) — *Hesperis matronalis*. **Escapes gardens and spreads**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/index.md).
 Photo: Anneli Salo; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/).
- [Diffuse knapweed](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/) — *Centaurea diffusa*. **Skin irritation; tumbling seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/index.md).
 Photo: Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/).
- [Dyer’s woad](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/) — *Isatis tinctoria*. **Persistent seed spread**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/index.md).
 Photo: Reuven Martin; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/).
- [Elongated mustard](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/) — *Brassica elongata*. **Early detection priority in dry disturbed land**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/index.md).
 Photo: Dmitriy Bochkov; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/).
- [Eurasian watermilfoil](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/) — *Myriophyllum spicatum*. **Fragments spread dense aquatic growth**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md).
 Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/).
- [Field bindweed](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/) — *Convolvulus arvensis*. **Smothers plants; livestock concern**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md).
 Photo: Svklimkin; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/).
- [Flowering rush](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/) — *Butomus umbellatus*. **Small fragments spread aquatic colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md).
 Photo: Jacek Pietruszewski; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/).
- [Giant knotweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/) — *Reynoutria sachalinensis*. **Very persistent riparian colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/index.md).
 Photo: Oleksandr Shynder; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/).
- [Giant reed](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/) — *Arundo donax*. **Dense stands displace riparian plants**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/).
- [Giant salvinia](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/) — *Salvinia molesta*. **Floating mats harm aquatic habitat**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md).
 Photo: Ixitixel; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/).
- [Green foxtail](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/) — *Setaria viridis*. **Identify the grass behind the name “foxtail”**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/index.md).
 Photo: Petr Filippov; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/).
- [Hairy willow-herb](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/) — *Epilobium hirsutum*. **Spreads through wetland vegetation**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/index.md).
 Photo: Mathias keraudren; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/).
- [Halogeton](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/) — *Halogeton glomeratus*. **Severe oxalate poisoning in livestock**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/).
- [Henbit](https://denson.github.io/colorado-weed-field-guide/plants/henbit/) — *Lamium amplexicaule*. **An early-flowering weed with useful nectar**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/henbit/index.md).
 Photo: Patrick Alexander from Las Cruces, NM; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/henbit/).
- [Hoary cress](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/) — *Lepidium draba*. **Spreading roots; possible livestock poisoning**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/index.md).
 Photo: Katrin Schneider / korina.info; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/).
- [Houndstongue](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/) — *Cynoglossum officinale*. **Toxic to livestock**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md).
 Photo: Bernd Haynold; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/).
- [Spotted × diffuse knapweed hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/) — *Centaurea × psammogena*. **Hybrid identification needs expert review**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/index.md).
 Photo: Tyler; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/).
- [Yellow × Dalmatian toadflax hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/) — *Linaria vulgaris × Linaria dalmatica*. **Variable hybrid; persistent spreading roots**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/index.md).
 Photo: Sharlene E. Sing, USDA Forest Service, Rocky Mountain Research Station; Public domain (U.S. federal employee work). [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/).
- [Hydrilla](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/) — *Hydrilla verticillata*. **Dense aquatic growth; wildlife disease association**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md).
 Photo: Stanislav Murashkin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/).
- [Japanese knotweed](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/) — *Reynoutria japonica*. **Root and stem fragments regrow**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md).
 Photo: Michael Gasperl ( Migas ); CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/).
- [Jimsonweed](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/) — *Datura stramonium*. **Serious poisoning risk to people and animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/).
- [Johnsongrass](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/) — *Sorghum halepense*. **Livestock cyanide risk; added fire fuel**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md).
 Photo: Jim Conrad; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/).
- [Jointed goatgrass](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/) — *Aegilops cylindrica*. **Wheat-field and rangeland seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/).
- [Kochia](https://denson.github.io/colorado-weed-field-guide/plants/kochia/) — *Bassia scoparia*. **Tumbling seed spread; livestock poisoning risk**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md).
 Photo: WildBoar; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/kochia/).
- [Large crabgrass](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/) — *Digitaria sanguinalis*. **Fast seed production in thin lawns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/).
- [Leafy spurge](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/) — *Euphorbia esula*. **Irritating sap; eye injury risk**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/).
- [Mayweed chamomile](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/) — *Anthemis cotula*. **Crop weed with unpleasant-smelling foliage**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/index.md).
 Photo: NY State IPM Program at Cornell University from New York, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/).
- [Meadow knapweed](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/) — *Centaurea × moncktonii*. **Outcompetes pasture and meadow plants**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/index.md).
 Photo: Eric Coombs, Oregon Department of Agriculture, Bugwood.org; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/).
- [Mediterranean sage](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/) — *Salvia aethiopis*. **Tumbles and spreads seed through rangeland**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/).
- [Medusahead](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/) — *Taeniatherum caput-medusae*. **Barbed awns; persistent fire-promoting thatch**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/).
- [Moth mullein](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/) — *Verbascum blattaria*. **Long-lived seeds sustain infestations**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/).
- [Musk thistle](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/) — *Carduus nutans*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/index.md).
 Photo: Robert Flogaus-Faust; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/).
- [Myrtle spurge](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/) — *Euphorbia myrsinites*. **Poisonous · Eye & skin injury**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md).
 Photo: Flocci Nivis; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/).
- [Narrow-leaved Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/) — *Linaria genistifolia*. **Listed taxon with difficult identification**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/).
- [Orange hawkweed](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/) — *Pilosella aurantiaca*. **Runners crowd lawns and mountain meadows**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/index.md).
 Photo: Tom Norton; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/).
- [Oxeye daisy](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/) — *Leucanthemum vulgare*. **Toxic to dogs and cats; dermatitis**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/).
- [Parrotfeather](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/) — *Myriophyllum aquaticum*. **Aquatic mats obstruct waterways**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md).
 Photo: Quillipede; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/).
- [Perennial pepperweed](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/) — *Lepidium latifolium*. **Deep roots form persistent wetland colonies**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/).
- [Perennial sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/) — *Sonchus arvensis*. **Persistent underground spread**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/index.md).
 Photo: Gabriele Kothe-Heinrich; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/).
- [Plumeless thistle](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/) — *Carduus acanthoides*. **Sharp spines; pasture competition**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/index.md).
 Photo: Dmitry Makeev; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/).
- [Poison hemlock](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/) — *Conium maculatum*. **Poisonous to people & animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/).
- [Prickly lettuce](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/) — *Lactuca serriola*. **Prickly leaves and prolific windborne seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/index.md).
 Photo: Teun Spaans (TeunSpaans); Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/).
- [Prickly sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/) — *Sonchus asper*. **Spiny leaves and rapid seed production**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/index.md).
 Photo: Didier Descouens; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/).
- [Prostrate knotweed](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/) — *Polygonum aviculare*. **A mat-forming weed of compacted ground**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/).
- [Puncturevine / goathead](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/) — *Tribulus terrestris*. **Sharp burs · Animal injury**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md).
 Photo: Forest & Kim Starr; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/).
- [Purple loosestrife](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/) — *Lythrum salicaria*. **Crowds out wetland vegetation**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md).
 Photo: Douglas Goldman; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/).
- [Quackgrass](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/) — *Elymus repens*. **Rhizome fragments regrow in lawns and gardens**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/).
- [Redroot pigweed](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/) — *Amaranthus retroflexus*. **Crop competition; nitrate and oxalate livestock risk**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md).
 Photo: Lynk media; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/).
- [Redstem filaree](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/) — *Erodium cicutarium*. **Seeds spread through lawns and pasture**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/index.md).
 Photo: Follavoine / follavoine.net; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/).
- [Rush skeletonweed](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/) — *Chondrilla juncea*. **Deep roots and fragments sustain spread**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/index.md).
 Photo: Zihao Wang; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/).
- [Russian knapweed](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/) — *Rhaponticum repens*. **Toxic to horses**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md).
 Photo: Amirh. absnd; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/).
- [Russian olive](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/) — *Elaeagnus angustifolia*. **Thorns; riparian habitat concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md).
 Photo: Georg Slickers; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/).
- [Russian thistle](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/) — *Salsola tragus*. **Prickly tumbleweeds; livestock and fire hazards**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/).
- [Scentless chamomile](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/) — *Tripleurospermum inodorum*. **Prolific seeds; reported livestock irritation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/).
- [Scotch thistle](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/) — *Onopordum acanthium*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/).
- [Shepherd’s purse](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/) — *Capsella bursa-pastoris*. **An early-seeding lawn and garden weed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/).
- [Siberian elm](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/) — *Ulmus pumila*. **Numerous seedlings; weak branches**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/index.md).
 Photo: Shizhao; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/).
- [Spotted knapweed](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/) — *Centaurea stoebe*. **Competes with native vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/index.md).
 Photo: Alan Vernon; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/).
- [Squarrose knapweed](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/) — *Centaurea virgata*. **Spiny seedheads; loss of rangeland forage**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/index.md).
 Photo: Alexander Dubynin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/).
- [Sulfur cinquefoil](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/) — *Potentilla recta*. **Persistent pasture and roadside weed**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/).
- [Tall buttercup](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/) — *Ranunculus acris*. **Fresh plant irritation and animal poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md).
 Photo: Daniel Cahen; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/).
- [Tamarisk](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/) — *Tamarix ramosissima*. **Alters riparian vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md).
 Photo: Jerzy Opioła; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/).
- [Tansy ragwort](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/) — *Jacobaea vulgaris*. **Poisonous to livestock; harmful alkaloids**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md).
 Photo: jamie-aa; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/).
- [Taurian thistle](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/) — *Onopordum tauricum*. **Sharp spines; taxon listed as Scotch thistle**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/index.md).
 Photo: Louis Aureglia; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/).
- [Tree of heaven](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/) — *Ailanthus altissima*. **Root suckers form persistent thickets**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md).
 Photo: Darkone; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/).
- [Tumble mustard](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/) — *Sisymbrium altissimum*. **Another tumbleweed: brittle plants scatter persistent seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md).
 Photo: Ben Keen; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/).
- [Velvetleaf](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/) — *Abutilon theophrasti*. **Persistent seeds and strong crop competition**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/index.md).
 Photo: Salicyna; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/).
- [Ventenata](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/) — *Ventenata dubia*. **Displaces forage and native grassland**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md).
 Photo: Matt Lavin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/).
- [White clover](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/) — *Trifolium repens*. **A spreading lawn plant with pollinator value**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/index.md).
 Photo: Ivar Leidus; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/).
- [White sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/) — *Melilotus albus*. **Moldy sweetclover hay can cause dangerous bleeding**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/).
- [Wild caraway](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/) — *Carum carvi*. **Spreads by seed; pet safety concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/).
- [Wild carrot](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/) — *Daucus carota*. **Do not confuse it with highly poisonous hemlocks**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/).
- [Wild parsnip](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/) — *Pastinaca sativa*. **Sap plus sunlight can cause severe skin burns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/).
- [Wild proso millet](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/) — *Panicum miliaceum*. **Seed contamination and crop competition**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md).
 Photo: Kurt Stüber; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/).
- [Yellow flag iris](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/) — *Iris pseudacorus*. **Ingestion concern; invasive wetland colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md).
 Photo: Kailey Alderfer; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/).
- [Yellow nutsedge](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/) — *Cyperus esculentus*. **Underground tubers sustain infestations**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/).
- [Yellow starthistle](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/) — *Centaurea solstitialis*. **Severe horse poisoning; sharp spines**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md).
 Photo: Юрий Данилевский (Yuriy Danilevsky); CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/).
- [Yellow sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/) — *Melilotus officinalis*. **Moldy sweetclover hay can cause dangerous bleeding**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/).
- [Yellow toadflax](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/) — *Linaria vulgaris*. **Spreads from roots; livestock concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/index.md).
 Photo: Michael H. Lemmer; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/).
# Appendix for agents
Category membership is editorial navigation. Native plants can also be xeriscape plants; noxious-list class is separate from toxicity. Follow the individual profiles for claim scope, caveats, and photo attribution. This is a selected catalog, not the entire Colorado flora.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/native/index.md
---
{}
---
# Native volunteers
Native plants that can volunteer or spread where they are not wanted. Their ecological value and their hazards deserve separate consideration. Regional and taxonomic limits are explained in the profiles.
29 plants in this view; 154 profiles and 462 photographs in the guide.
[Biggest concerns](https://denson.github.io/colorado-weed-field-guide/biggest-concerns/) · [Coverage: all 82 state-list entries](https://denson.github.io/colorado-weed-field-guide/coverage/) · [Exposure and safety guide](https://denson.github.io/colorado-weed-field-guide/safety/) · [Learn to use this guide](https://denson.github.io/colorado-weed-field-guide/companion/)
## Native volunteers
- [Black greasewood](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/) — *Sarcobatus vermiculatus*. **Oxalate poisoning can be fatal to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md).
 Photo: John Gaskin; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/).
- [Broom snakeweed](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/) — *Gutierrezia sarothrae*. **Livestock poisoning and abortion risk when heavily eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md).
 Photo: CK2AZ; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/).
- [Buffalobur](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/) — *Solanum rostratum*. **Sharp spines; toxic to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md).
 Photo: Juan Carlos Fonseca Mata; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/).
- [Canada goldenrod](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/) — *Solidago canadensis*. **Spreads by roots and seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/index.md).
 Photo: Étienne Lacroix-Carignan; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/canada-goldenrod/).
- [Catchweed bedstraw](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/) — *Galium aparine*. **Hooked hairs and burrs cling to fur and clothing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/).
- [Common blue violet](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/) — *Viola sororia*. **A native volunteer; identify the species before removing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/index.md).
 Photo: James Steakley; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-blue-violet/).
- [Common ragweed](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/) — *Ambrosia artemisiifolia*. **Pollen allergy; skin irritation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/).
- [Common sunflower](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/) — *Helianthus annuus*. **Listed non-toxic to dogs & cats**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/index.md).
 Photo: Michelle W. （鍾偉瑋）; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-sunflower/).
- [Curlycup gumweed](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/) — *Grindelia squarrosa*. **Sticky resin and conditional selenium concern**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/index.md).
 Photo: Jesse Grove; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/curlycup-gumweed/).
- [Foxtail barley](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/) — *Hordeum jubatum*. **Barbed seed awns injure animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md).
 Photo: Diego Delso; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/).
- [Giant ragweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/) — *Ambrosia trifida*. **Allergenic pollen and strong competition in disturbed ground**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md).
 Photo: GTBacchus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/).
- [Golden banner](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/) — *Thermopsis divaricarpa*. **May poison livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/index.md).
 Photo: Laura J. Costello; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/golden-banner/).
- [Hemp dogbane](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/) — *Apocynum cannabinum*. **Cardiac-glycoside poisoning hazard for people and animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/).
- [Horseweed](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/) — *Erigeron canadensis*. **Fast windborne spread; some populations resist herbicides**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md).
 Photo: Enrico Blasutto; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/).
- [Low larkspur](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/) — *Delphinium nuttallianum*. **Serious livestock and pet poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md).
 Photo: NPS; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/).
- [Meadow death camas](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/) — *Toxicoscordion venenosum*. **Potentially fatal ingestion; onion-like bulbs**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md).
 Photo: NPS Photo; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/).
- [Netseed lambsquarters](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/) — *Chenopodium berlandieri*. **A fast-growing volunteer; pet toxicity remains unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/index.md).
 Photo: Matt Lavin; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/netseed-lambsquarters/).
- [Prairie sage](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/) — *Artemisia ludoviciana*. **Spreading roots; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prairie-sage/).
- [Showy milkweed](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/) — *Asclepias speciosa*. **Toxic if eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md).
 Photo: Andrey Zharkikh; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/).
- [Silverleaf nightshade](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/) — *Solanum elaeagnifolium*. **Toxic leaves and berries; persistent spreading roots**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md).
 Photo: Sam Kieschnick; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/).
- [Snow-on-the-mountain](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/) — *Euphorbia marginata*. **Latex can damage skin and eyes; toxic if eaten**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md).
 Photo: Mark G; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/).
- [Spotted spurge](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/) — *Euphorbia maculata*. **Milky sap can injure skin and eyes; keep pets from chewing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/).
- [Stinging nettle](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/) — *Urtica dioica*. **Stinging hairs; this profile covers a taxonomic complex**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md).
 Photo: Przykuta; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/).
- [Tall larkspur](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/) — *Delphinium barbeyi*. **Serious livestock and pet poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md).
 Photo: Ms. Sticky; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/).
- [Western poison ivy](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/) — *Toxicodendron rydbergii*. **Skin-rash oil can travel on pet fur**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md).
 Photo: Andrey Zharkikh from Salt Lake City, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/).
- [Western ragweed](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/) — *Ambrosia psilostachya*. **A persistent perennial ragweed; allergy detail still under review**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md).
 Photo: Zihao Wang; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/).
- [Western water hemlock](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/) — *Cicuta douglasii*. **Potentially fatal poisoning; wetland look-alike danger**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md).
 Photo: Lee Cain; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/).
- [Western whorled milkweed](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/) — *Asclepias subverticillata*. **High livestock toxicity**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md).
 Photo: Patrick Alexander from Las Cruces, NM; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/).
- [White locoweed](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/) — *Oxytropis sericea*. **Toxic to livestock**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/).
# Appendix for agents
Category membership is editorial navigation. Native plants can also be xeriscape plants; noxious-list class is separate from toxicity. Follow the individual profiles for claim scope, caveats, and photo attribution. This is a selected catalog, not the entire Colorado flora.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/native/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/native/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/native/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/xeriscape/index.md
---
{}
---
# Xeriscape spreaders
Plants used in dry gardens that may spread beyond their allotted space. This group includes Colorado natives and introduced ornamentals.
14 plants in this view; 154 profiles and 462 photographs in the guide.
[Biggest concerns](https://denson.github.io/colorado-weed-field-guide/biggest-concerns/) · [Coverage: all 82 state-list entries](https://denson.github.io/colorado-weed-field-guide/coverage/) · [Exposure and safety guide](https://denson.github.io/colorado-weed-field-guide/safety/) · [Learn to use this guide](https://denson.github.io/colorado-weed-field-guide/companion/)
## Xeriscape spreaders
- [Big sagebrush](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/) — *Artemisia tridentata*. **Valuable native habitat; subspecies and pet evidence need care**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/index.md).
 Photo: Matt Lavin; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/big-sagebrush/).
- [Blanketflower](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/) — *Gaillardia aristata*. **Contact dermatitis possible**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/index.md).
 Photo: NPS / Jacob W. Frank; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/blanketflower/).
- [Catmint](https://denson.github.io/colorado-weed-field-guide/plants/catmint/) — *Nepeta × faassenii*. **Spreading clumps; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/catmint/index.md).
 Photo: Didier Descouens; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/catmint/).
- [Common yarrow](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/) — *Achillea millefolium*. **Toxic to pets · Skin irritation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/index.md).
 Photo: Petar Milošević; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-yarrow/).
- [Fernleaf yarrow](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/) — *Achillea filipendulina*. **Spreads; pet toxicity unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/index.md).
 Photo: Yerpo; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/fernleaf-yarrow/).
- [Fringed sage](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/) — *Artemisia frigida*. **Spreading growth; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/fringed-sage/).
- [Lamb’s-ear](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/) — *Stachys byzantina*. **Can spread; pet evidence gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/lambs-ear/).
- [Lewis blue flax](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/) — *Linum lewisii*. **Ingestion and contact concerns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/index.md).
 Photo: Walter Siegmund (talk); CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/lewis-blue-flax/).
- [Plains pricklypear](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/) — *Opuntia polyacantha*. **Sharp spines around paws, mouths and eyes**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md).
 Photo: eigenmotion; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/).
- [Red valerian](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/) — *Centranthus ruber*. **Self-seeds beyond garden beds**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/index.md).
 Photo: Robert Flogaus-Faust; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/red-valerian/).
- [Rubber rabbitbrush](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/) — *Ericameria nauseosa*. **A native low-water shrub that can spread readily**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/index.md).
 Photo: Ian Adams; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/rubber-rabbitbrush/).
- [Russian sage](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/) — *Salvia yangii*. **Spreads by suckers; pet evidence unresolved**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/index.md).
 Photo: Doronenko; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-sage/).
- [Snow-in-summer](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/) — *Cerastium tomentosum*. **Spreading habit · Safety gap**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/index.md).
 Photo: Salicyna; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/snow-in-summer/).
- [Soapweed yucca](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/) — *Yucca glauca*. **Sharp leaves · Toxic to pets**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/index.md).
 Photo: Alvesgaspar; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/soapweed-yucca/).
# Appendix for agents
Category membership is editorial navigation. Native plants can also be xeriscape plants; noxious-list class is separate from toxicity. Follow the individual profiles for claim scope, caveats, and photo attribution. This is a selected catalog, not the entire Colorado flora.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/xeriscape/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/xeriscape/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/xeriscape/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/invasive/index.md
---
{}
---
# Invasive & common weeds
State-listed noxious plants and common garden, crop and disturbed-ground weeds. Navigation does not assign native status or equal invasiveness to every plant. Legal weed class and toxicity are separate.
111 plants in this view; 154 profiles and 462 photographs in the guide.
[Biggest concerns](https://denson.github.io/colorado-weed-field-guide/biggest-concerns/) · [Coverage: all 82 state-list entries](https://denson.github.io/colorado-weed-field-guide/coverage/) · [Exposure and safety guide](https://denson.github.io/colorado-weed-field-guide/safety/) · [Learn to use this guide](https://denson.github.io/colorado-weed-field-guide/companion/)
## Invasive & common weeds
- [Absinth wormwood](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/) — *Artemisia absinthium*. **Ingestion toxicity and skin irritation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/index.md).
 Photo: Agnieszka Kwiecień, Nova; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/).
- [African rue](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/) — *Peganum harmala*. **Highly poisonous if eaten; deep-rooted invader**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md).
 Photo: Alex Abair; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/).
- [Annual sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/) — *Sonchus oleraceus*. **Windborne seed and crop-pest hosting**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/index.md).
 Photo: Miwasatoshi; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/annual-sowthistle/).
- [Bittersweet nightshade](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/) — *Solanum dulcamara*. **Poisonous berries and foliage**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/).
- [Black henbane](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/) — *Hyoscyamus niger*. **Highly poisonous; keep animals away**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/).
- [Bohemian knotweed](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/) — *Reynoutria × bohemica*. **Hybrid regrows from small fragments**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md).
 Photo: Patrick Hacker; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/).
- [Bouncingbet](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/) — *Saponaria officinalis*. **Saponins can cause digestive poisoning**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/index.md).
 Photo: Ryan Hodnett; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/).
- [Bulbous bluegrass](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/) — *Poa bulbosa*. **Early-season grass spreads by bulbils**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/).
- [Bull thistle](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/) — *Cirsium vulgare*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/index.md).
 Photo: Dominicus Johannes Bergsma; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/).
- [Camelthorn](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/) — *Alhagi maurorum*. **Thorns and deep spreading roots**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/index.md).
 Photo: Jesse Rorabaugh; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/).
- [Canada thistle](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/) — *Cirsium arvense*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md).
 Photo: Ivar Leidus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/).
- [Cheatgrass / downy brome](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/) — *Bromus tectorum*. **Grass awns · Fire hazard**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md).
 Photo: AnRo0002; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/).
- [Chicory](https://denson.github.io/colorado-weed-field-guide/plants/chicory/) — *Cichorium intybus*. **Roadside and pasture spread**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/chicory/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/chicory/).
- [Chinese clematis](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/) — *Clematis orientalis*. **Smothers vegetation; irritating plant compounds**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/).
- [Common burdock](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/) — *Arctium minus*. **Burs and fine bristles injure animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/).
- [Common chickweed](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/) — *Stellaria media*. **A cool-season weed that can seed while still small**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/index.md).
 Photo: Forest and Kim Starr; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-chickweed/).
- [Common cocklebur](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/) — *Xanthium strumarium*. **Burs catch in fur; seedlings and seeds are hazardous**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md).
 Photo: Franco Folini; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/).
- [Common crupina](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/) — *Crupina vulgaris*. **Dense stands reduce forage**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/index.md).
 Photo: Clément Maouche; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/).
- [Common dandelion](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/) — *Taraxacum officinale*. **Persistent lawn volunteer; sap can irritate skin**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md).
 Photo: FoeNyx; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/).
- [Common lambsquarters](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/) — *Chenopodium album*. **Prolific garden weed; ingestion caution**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/index.md).
 Photo: Matt Lavin; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-lambsquarters/).
- [Common mallow](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/) — *Malva neglecta*. **Tough taproot and persistent lawn seedbank**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/index.md).
 Photo: NY State IPM Program at Cornell University from New York, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-mallow/).
- [Common mullein](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/) — *Verbascum thapsus*. **Dense rosettes and persistent volunteers**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/).
- [Common purslane](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/) — *Portulaca oleracea*. **Pet ingestion hazard despite human food uses**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-purslane/).
- [Common St. Johnswort](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/) — *Hypericum perforatum*. **Photosensitivity and animal exposure concerns**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md).
 Photo: W. Bulach; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/).
- [Common tansy](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/) — *Tanacetum vulgare*. **Toxic ingestion; contact dermatitis**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/index.md).
 Photo: Agnes Monkelbaan; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/).
- [Common teasel](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/) — *Dipsacus fullonum*. **Prickly heads; prolific seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/).
- [Creeping woodsorrel](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/) — *Oxalis corniculata*. **Oxalate-containing plant; keep pets from grazing**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/index.md).
 Photo: Forest & Kim Starr; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/creeping-woodsorrel/).
- [Crownvetch](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/) — *Securigera varia*. **Toxic to horses; spreading roots can smother vegetation**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md).
 Photo: Dale Knox; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/).
- [Curly dock](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/) — *Rumex crispus*. **Soluble oxalates; persistent roots and seeds**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/curly-dock/).
- [Cutleaf teasel](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/) — *Dipsacus laciniatus*. **Prickly stands can displace native vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/index.md).
 Photo: Alexander Klink; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/).
- [Cypress spurge](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/) — *Euphorbia cyparissias*. **Sap can injure skin and eyes**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md).
 Photo: Tom Scavo; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/).
- [Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/) — *Linaria dalmatica*. **Spreads from roots; livestock concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/index.md).
 Photo: Walter Siegmund (talk); CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/).
- [Dame’s rocket](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/) — *Hesperis matronalis*. **Escapes gardens and spreads**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/index.md).
 Photo: Anneli Salo; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/).
- [Diffuse knapweed](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/) — *Centaurea diffusa*. **Skin irritation; tumbling seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/index.md).
 Photo: Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/).
- [Dyer’s woad](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/) — *Isatis tinctoria*. **Persistent seed spread**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/index.md).
 Photo: Reuven Martin; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/).
- [Elongated mustard](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/) — *Brassica elongata*. **Early detection priority in dry disturbed land**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/index.md).
 Photo: Dmitriy Bochkov; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/).
- [Eurasian watermilfoil](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/) — *Myriophyllum spicatum*. **Fragments spread dense aquatic growth**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md).
 Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/).
- [Field bindweed](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/) — *Convolvulus arvensis*. **Smothers plants; livestock concern**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md).
 Photo: Svklimkin; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/).
- [Flowering rush](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/) — *Butomus umbellatus*. **Small fragments spread aquatic colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md).
 Photo: Jacek Pietruszewski; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/).
- [Giant knotweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/) — *Reynoutria sachalinensis*. **Very persistent riparian colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/index.md).
 Photo: Oleksandr Shynder; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/).
- [Giant reed](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/) — *Arundo donax*. **Dense stands displace riparian plants**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/).
- [Giant salvinia](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/) — *Salvinia molesta*. **Floating mats harm aquatic habitat**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md).
 Photo: Ixitixel; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/).
- [Green foxtail](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/) — *Setaria viridis*. **Identify the grass behind the name “foxtail”**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/index.md).
 Photo: Petr Filippov; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/green-foxtail/).
- [Hairy willow-herb](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/) — *Epilobium hirsutum*. **Spreads through wetland vegetation**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/index.md).
 Photo: Mathias keraudren; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/).
- [Halogeton](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/) — *Halogeton glomeratus*. **Severe oxalate poisoning in livestock**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/).
- [Henbit](https://denson.github.io/colorado-weed-field-guide/plants/henbit/) — *Lamium amplexicaule*. **An early-flowering weed with useful nectar**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/henbit/index.md).
 Photo: Patrick Alexander from Las Cruces, NM; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/henbit/).
- [Hoary cress](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/) — *Lepidium draba*. **Spreading roots; possible livestock poisoning**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/index.md).
 Photo: Katrin Schneider / korina.info; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/).
- [Houndstongue](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/) — *Cynoglossum officinale*. **Toxic to livestock**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md).
 Photo: Bernd Haynold; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/).
- [Spotted × diffuse knapweed hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/) — *Centaurea × psammogena*. **Hybrid identification needs expert review**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/index.md).
 Photo: Tyler; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/).
- [Yellow × Dalmatian toadflax hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/) — *Linaria vulgaris × Linaria dalmatica*. **Variable hybrid; persistent spreading roots**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/index.md).
 Photo: Sharlene E. Sing, USDA Forest Service, Rocky Mountain Research Station; Public domain (U.S. federal employee work). [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/).
- [Hydrilla](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/) — *Hydrilla verticillata*. **Dense aquatic growth; wildlife disease association**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md).
 Photo: Stanislav Murashkin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/).
- [Japanese knotweed](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/) — *Reynoutria japonica*. **Root and stem fragments regrow**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md).
 Photo: Michael Gasperl ( Migas ); CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/).
- [Jimsonweed](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/) — *Datura stramonium*. **Serious poisoning risk to people and animals**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/).
- [Johnsongrass](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/) — *Sorghum halepense*. **Livestock cyanide risk; added fire fuel**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md).
 Photo: Jim Conrad; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/).
- [Jointed goatgrass](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/) — *Aegilops cylindrica*. **Wheat-field and rangeland seed spread**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/).
- [Kochia](https://denson.github.io/colorado-weed-field-guide/plants/kochia/) — *Bassia scoparia*. **Tumbling seed spread; livestock poisoning risk**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md).
 Photo: WildBoar; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/kochia/).
- [Large crabgrass](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/) — *Digitaria sanguinalis*. **Fast seed production in thin lawns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/large-crabgrass/).
- [Leafy spurge](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/) — *Euphorbia esula*. **Irritating sap; eye injury risk**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/).
- [Mayweed chamomile](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/) — *Anthemis cotula*. **Crop weed with unpleasant-smelling foliage**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/index.md).
 Photo: NY State IPM Program at Cornell University from New York, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/).
- [Meadow knapweed](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/) — *Centaurea × moncktonii*. **Outcompetes pasture and meadow plants**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/index.md).
 Photo: Eric Coombs, Oregon Department of Agriculture, Bugwood.org; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/).
- [Mediterranean sage](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/) — *Salvia aethiopis*. **Tumbles and spreads seed through rangeland**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/).
- [Medusahead](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/) — *Taeniatherum caput-medusae*. **Barbed awns; persistent fire-promoting thatch**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/).
- [Moth mullein](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/) — *Verbascum blattaria*. **Long-lived seeds sustain infestations**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/).
- [Musk thistle](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/) — *Carduus nutans*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/index.md).
 Photo: Robert Flogaus-Faust; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/).
- [Myrtle spurge](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/) — *Euphorbia myrsinites*. **Poisonous · Eye & skin injury**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md).
 Photo: Flocci Nivis; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/).
- [Narrow-leaved Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/) — *Linaria genistifolia*. **Listed taxon with difficult identification**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/).
- [Orange hawkweed](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/) — *Pilosella aurantiaca*. **Runners crowd lawns and mountain meadows**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/index.md).
 Photo: Tom Norton; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/).
- [Oxeye daisy](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/) — *Leucanthemum vulgare*. **Toxic to dogs and cats; dermatitis**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/).
- [Parrotfeather](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/) — *Myriophyllum aquaticum*. **Aquatic mats obstruct waterways**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md).
 Photo: Quillipede; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/).
- [Perennial pepperweed](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/) — *Lepidium latifolium*. **Deep roots form persistent wetland colonies**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/).
- [Perennial sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/) — *Sonchus arvensis*. **Persistent underground spread**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/index.md).
 Photo: Gabriele Kothe-Heinrich; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/).
- [Plumeless thistle](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/) — *Carduus acanthoides*. **Sharp spines; pasture competition**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/index.md).
 Photo: Dmitry Makeev; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/).
- [Poison hemlock](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/) — *Conium maculatum*. **Poisonous to people & animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/).
- [Prickly lettuce](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/) — *Lactuca serriola*. **Prickly leaves and prolific windborne seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/index.md).
 Photo: Teun Spaans (TeunSpaans); Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prickly-lettuce/).
- [Prickly sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/) — *Sonchus asper*. **Spiny leaves and rapid seed production**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/index.md).
 Photo: Didier Descouens; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prickly-sowthistle/).
- [Prostrate knotweed](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/) — *Polygonum aviculare*. **A mat-forming weed of compacted ground**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/prostrate-knotweed/).
- [Puncturevine / goathead](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/) — *Tribulus terrestris*. **Sharp burs · Animal injury**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md).
 Photo: Forest & Kim Starr; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/).
- [Purple loosestrife](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/) — *Lythrum salicaria*. **Crowds out wetland vegetation**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md).
 Photo: Douglas Goldman; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/).
- [Quackgrass](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/) — *Elymus repens*. **Rhizome fragments regrow in lawns and gardens**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/).
- [Redroot pigweed](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/) — *Amaranthus retroflexus*. **Crop competition; nitrate and oxalate livestock risk**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md).
 Photo: Lynk media; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/).
- [Redstem filaree](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/) — *Erodium cicutarium*. **Seeds spread through lawns and pasture**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/index.md).
 Photo: Follavoine / follavoine.net; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/).
- [Rush skeletonweed](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/) — *Chondrilla juncea*. **Deep roots and fragments sustain spread**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/index.md).
 Photo: Zihao Wang; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/).
- [Russian knapweed](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/) — *Rhaponticum repens*. **Toxic to horses**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md).
 Photo: Amirh. absnd; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/).
- [Russian olive](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/) — *Elaeagnus angustifolia*. **Thorns; riparian habitat concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md).
 Photo: Georg Slickers; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/).
- [Russian thistle](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/) — *Salsola tragus*. **Prickly tumbleweeds; livestock and fire hazards**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/).
- [Scentless chamomile](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/) — *Tripleurospermum inodorum*. **Prolific seeds; reported livestock irritation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/).
- [Scotch thistle](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/) — *Onopordum acanthium*. **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/).
- [Shepherd’s purse](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/) — *Capsella bursa-pastoris*. **An early-seeding lawn and garden weed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/shepherds-purse/).
- [Siberian elm](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/) — *Ulmus pumila*. **Numerous seedlings; weak branches**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/index.md).
 Photo: Shizhao; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/).
- [Spotted knapweed](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/) — *Centaurea stoebe*. **Competes with native vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/index.md).
 Photo: Alan Vernon; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/).
- [Squarrose knapweed](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/) — *Centaurea virgata*. **Spiny seedheads; loss of rangeland forage**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/index.md).
 Photo: Alexander Dubynin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/).
- [Sulfur cinquefoil](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/) — *Potentilla recta*. **Persistent pasture and roadside weed**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/).
- [Tall buttercup](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/) — *Ranunculus acris*. **Fresh plant irritation and animal poisoning hazard**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md).
 Photo: Daniel Cahen; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/).
- [Tamarisk](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/) — *Tamarix ramosissima*. **Alters riparian vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md).
 Photo: Jerzy Opioła; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/).
- [Tansy ragwort](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/) — *Jacobaea vulgaris*. **Poisonous to livestock; harmful alkaloids**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md).
 Photo: jamie-aa; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/).
- [Taurian thistle](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/) — *Onopordum tauricum*. **Sharp spines; taxon listed as Scotch thistle**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/index.md).
 Photo: Louis Aureglia; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/).
- [Tree of heaven](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/) — *Ailanthus altissima*. **Root suckers form persistent thickets**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md).
 Photo: Darkone; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/).
- [Tumble mustard](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/) — *Sisymbrium altissimum*. **Another tumbleweed: brittle plants scatter persistent seed**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md).
 Photo: Ben Keen; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/).
- [Velvetleaf](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/) — *Abutilon theophrasti*. **Persistent seeds and strong crop competition**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/index.md).
 Photo: Salicyna; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/).
- [Ventenata](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/) — *Ventenata dubia*. **Displaces forage and native grassland**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md).
 Photo: Matt Lavin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/).
- [White clover](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/) — *Trifolium repens*. **A spreading lawn plant with pollinator value**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/index.md).
 Photo: Ivar Leidus; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-clover/).
- [White sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/) — *Melilotus albus*. **Moldy sweetclover hay can cause dangerous bleeding**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/).
- [Wild caraway](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/) — *Carum carvi*. **Spreads by seed; pet safety concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/).
- [Wild carrot](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/) — *Daucus carota*. **Do not confuse it with highly poisonous hemlocks**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-carrot/).
- [Wild parsnip](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/) — *Pastinaca sativa*. **Sap plus sunlight can cause severe skin burns**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/).
- [Wild proso millet](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/) — *Panicum miliaceum*. **Seed contamination and crop competition**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md).
 Photo: Kurt Stüber; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/).
- [Yellow flag iris](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/) — *Iris pseudacorus*. **Ingestion concern; invasive wetland colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md).
 Photo: Kailey Alderfer; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/).
- [Yellow nutsedge](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/) — *Cyperus esculentus*. **Underground tubers sustain infestations**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/).
- [Yellow starthistle](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/) — *Centaurea solstitialis*. **Severe horse poisoning; sharp spines**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md).
 Photo: Юрий Данилевский (Yuriy Danilevsky); CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/).
- [Yellow sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/) — *Melilotus officinalis*. **Moldy sweetclover hay can cause dangerous bleeding**. [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/).
- [Yellow toadflax](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/) — *Linaria vulgaris*. **Spreads from roots; livestock concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Full Markdown profile](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/index.md).
 Photo: Michael H. Lemmer; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/).
# Appendix for agents
Category membership is editorial navigation. Native plants can also be xeriscape plants; noxious-list class is separate from toxicity. Follow the individual profiles for claim scope, caveats, and photo attribution. This is a selected catalog, not the entire Colorado flora.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/invasive/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/invasive/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/invasive/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/coverage/index.md
---
{
"source_ids": [
"C-descriptions",
"CO-rules-2025",
"Corteva-west",
"Fremont-list-definitions"
]
}
---
# Coverage checklist
**82 of 82 state-list entries have illustrated profiles.** The guide contains 154 profiles and 462 distinct photographs overall.
Baseline: [Colorado noxious-weed rule, effective 2025-05-15](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2), parts 3.1, 4.1 and 5.1. Source checked 2026-09-07T01:07:48+00:00.
A finite regulatory baseline, not a claim to encompass every plant that could be considered a weed. Salt cedar is one listing row containing two named species. Hybrids retain separate rows.
Coverage means that a profile discusses the entry, with three source-identified photographs and explicit evidence limits. It does not mean every listed subspecies, hybrid or local population has been independently identified or that pet toxicology is complete.
## What the state lists mean
These categories describe weed management requirements. They are separate from danger ratings for people, pets, livestock and other plants.
| State list | Meaning |
|---|---|
| **List A — Eradicate** | Uncommon in Colorado. All populations are designated for eradication statewide. |
| **List B — Stop the spread** | Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. |
| **List C — Manage widespread weeds** | Widespread and well established. Control is recommended by the state; local governments may require management. |
Source: [Fremont-list-definitions: Weed Identification: Colorado List A, B and C definitions](https://fremontcountyco.gov/weed-control/weed-identification).
## Beyond the state lists
Only the specified finite Corteva Western Rangeland guide and CSU Weed Descriptions article; not every page on either website. Missing topics are research candidates, not confirmed Colorado occurrences.
| Compared publication | Topics | Fully matched | Partly represented | Still missing |
|---|---:|---:|---:|---:|
| [CSU Weed Descriptions](https://extension.colostate.edu/resource/weed-descriptions/) | 37 | 36 | 1 | 0 |
| [Corteva Western Rangeland guide](https://online.flippingbook.com/view/847083821/) | 84 | 50 | 7 | 27 |
Dedicated source topic, not species count or clinical completeness. Compound and genus topics remain partial until all named components are covered. Every plant page displays its research status; a profile is not a completed safety review. The [full comparison and source records](https://denson.github.io/colorado-weed-field-guide/coverage.json) preserve each match and gap.
### Next research candidates
These topics remain missing or partly covered. Colorado occurrence, exact identity and hazards need review before expansion.
| Source | Topic | Coverage | Remaining taxa or groups |
|---|---|---|---|
| CSU Weed Descriptions | [Wild Violet](https://extension.colostate.edu/resource/weed-descriptions/) | partial | Viola spp. |
| Corteva Western Rangeland guide | [Bitter sneezeweed](https://online.flippingbook.com/view/847083821/) | none | Helenium badium, Helenium amarum |
| Corteva Western Rangeland guide | [Annual broomweed](https://online.flippingbook.com/view/847083821/) | none | Amphiachyris dracunculoides |
| Corteva Western Rangeland guide | [Woolly croton / goatweed](https://online.flippingbook.com/view/847083821/) | none | Croton texensis |
| Corteva Western Rangeland guide | [Cutleaf evening primrose](https://online.flippingbook.com/view/847083821/) | none | Oenothera laciniata |
| Corteva Western Rangeland guide | [Fleabane](https://online.flippingbook.com/view/847083821/) | none | Erigeron annuus |
| Corteva Western Rangeland guide | [Carolina geranium](https://online.flippingbook.com/view/847083821/) | none | Geranium carolinianum |
| Corteva Western Rangeland guide | [Hemp](https://online.flippingbook.com/view/847083821/) | none | Cannabis sativa |
| Corteva Western Rangeland guide | [Marshelder / sumpweed](https://online.flippingbook.com/view/847083821/) | none | Iva annua |
| Corteva Western Rangeland guide | [Hedge and tumble mustard](https://online.flippingbook.com/view/847083821/) | partial | Sisymbrium officinale |
| Corteva Western Rangeland guide | [Wild mustard](https://online.flippingbook.com/view/847083821/) | none | Sinapis arvensis |
| Corteva Western Rangeland guide | [Spiny amaranth](https://online.flippingbook.com/view/847083821/) | none | Amaranthus spinosus |
| Corteva Western Rangeland guide | [Common and giant ragweed](https://online.flippingbook.com/view/847083821/) | partial | UNRESOLVED giant ragweed label |
| Corteva Western Rangeland guide | [Lanceleaf ragweed](https://online.flippingbook.com/view/847083821/) | none | Ambrosia bidentata |
| Corteva Western Rangeland guide | [Prickly sida](https://online.flippingbook.com/view/847083821/) | none | Sida spinosa |
| Corteva Western Rangeland guide | [Pennsylvania and tufted smartweed](https://online.flippingbook.com/view/847083821/) | none | Persicaria pensylvanica, Persicaria longiseta |
| Corteva Western Rangeland guide | [Vetch](https://online.flippingbook.com/view/847083821/) | none | Vicia sativa |
| Corteva Western Rangeland guide | [Western bitterweed / bitter rubberweed](https://online.flippingbook.com/view/847083821/) | none | Hymenoxys odorata, Hymenoxys richardsonii |
| Corteva Western Rangeland guide | [Smooth and catchweed bedstraw](https://online.flippingbook.com/view/847083821/) | partial | Galium mollugo |
| Corteva Western Rangeland guide | [Bull nettle](https://online.flippingbook.com/view/847083821/) | none | Cnidoscolus texanus |
| Corteva Western Rangeland guide | [Dogfennel](https://online.flippingbook.com/view/847083821/) | none | Eupatorium capillifolium |
| Corteva Western Rangeland guide | [Goldenrod](https://online.flippingbook.com/view/847083821/) | partial | Solidago spp. |
| Corteva Western Rangeland guide | [Giant hogweed](https://online.flippingbook.com/view/847083821/) | none | Heracleum mantegazzianum |
| Corteva Western Rangeland guide | [Carolina and western horsenettle](https://online.flippingbook.com/view/847083821/) | none | Solanum carolinense, Solanum dimidiatum |
| Corteva Western Rangeland guide | [Tall and western ironweed](https://online.flippingbook.com/view/847083821/) | none | Vernonia gigantea, Vernonia baldwinii |
| Corteva Western Rangeland guide | [Brown and spotted knapweed](https://online.flippingbook.com/view/847083821/) | partial | Centaurea jacea |
| Corteva Western Rangeland guide | [Woolly locoweeds and crazyweeds](https://online.flippingbook.com/view/847083821/) | partial | Astragalus spp., Oxytropis spp. |
| Corteva Western Rangeland guide | [Broadleaf and narrowleaf plantain](https://online.flippingbook.com/view/847083821/) | none | Plantago major, Plantago lanceolata |
| Corteva Western Rangeland guide | [Sericea lespedeza](https://online.flippingbook.com/view/847083821/) | none | Lespedeza cuneata |
| Corteva Western Rangeland guide | [Threadleaf groundsel](https://online.flippingbook.com/view/847083821/) | none | Senecio douglasii |
| Corteva Western Rangeland guide | [Blue and hoary vervain](https://online.flippingbook.com/view/847083821/) | none | Verbena hastata, Verbena stricta |
| Corteva Western Rangeland guide | [Wingstem](https://online.flippingbook.com/view/847083821/) | none | Verbesina alternifolia |
| Corteva Western Rangeland guide | [Willows](https://online.flippingbook.com/view/847083821/) | none | Salix spp. |
| Corteva Western Rangeland guide | [Rabbitbrush](https://online.flippingbook.com/view/847083821/) | partial | Chrysothamnus spp. |
| Corteva Western Rangeland guide | [Buckbrush](https://online.flippingbook.com/view/847083821/) | none | Ceanothus cuneatus |
## List A — Eradicate · 27 entries
Uncommon in Colorado. All populations are designated for eradication statewide.
| State listing | Listed scientific name | Illustrated profile | Mapping and limits |
|---|---|---|---|
| African rue | *Peganum harmala* | [African rue](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/) | Exact listing name. |
| Camelthorn | *Alhagi maurorum* | [Camelthorn](https://denson.github.io/colorado-weed-field-guide/plants/camelthorn/) | Exact listing name. |
| Common crupina | *Crupina vulgaris* | [Common crupina](https://denson.github.io/colorado-weed-field-guide/plants/common-crupina/) | Exact listing name. |
| Cypress spurge | *Euphorbia cyparissias* | [Cypress spurge](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/) | Exact listing name. |
| Dyer's woad | *Isatis tinctoria* | [Dyer’s woad](https://denson.github.io/colorado-weed-field-guide/plants/dyers-woad/) | Exact listing name. |
| Elongated mustard | *Brassica elongata* | [Elongated mustard](https://denson.github.io/colorado-weed-field-guide/plants/elongated-mustard/) | Exact listing name. |
| Flowering rush | *Butomus umbellatus* | [Flowering rush](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/) | Exact listing name. |
| Giant reed | *Arundo donax* | [Giant reed](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/) | Exact listing name. |
| Giant salvinia | *Salvinia molesta* | [Giant salvinia](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/) | Exact listing name. |
| Hairy willow-herb | *Epilobium hirsutum* | [Hairy willow-herb](https://denson.github.io/colorado-weed-field-guide/plants/hairy-willow-herb/) | Exact listing name. |
| Hydrilla | *Hydrilla verticillata* | [Hydrilla](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/) | Exact listing name. |
| Japanese knotweed | *Fallopia japonica* | [Japanese knotweed](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Giant knotweed | *Fallopia sachalinense* | [Giant knotweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-knotweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Bohemian knotweed | *Fallopia x bohemicum* | [Bohemian knotweed](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Meadow knapweed | *Centaurea x moncktonii* | [Meadow knapweed](https://denson.github.io/colorado-weed-field-guide/plants/meadow-knapweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Mediterranean sage | *Salvia aethiopis* | [Mediterranean sage](https://denson.github.io/colorado-weed-field-guide/plants/mediterranean-sage/) | Exact listing name. |
| Medusahead | *Taeniatherum caput-medusae* | [Medusahead](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/) | Exact listing name. |
| Myrtle spurge | *Euphorbia myrsinites* | [Myrtle spurge](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/) | Exact listing name. |
| Orange hawkweed | *Hieracium aurantiacum* | [Orange hawkweed](https://denson.github.io/colorado-weed-field-guide/plants/orange-hawkweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Parrotfeather | *Myriophyllum aquaticum* | [Parrotfeather](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/) | Exact listing name. |
| Purple loosestrife | *Lythrum salicaria* | [Purple loosestrife](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/) | Exact listing name. |
| Rush skeletonweed | *Chondrilla juncea* | [Rush skeletonweed](https://denson.github.io/colorado-weed-field-guide/plants/rush-skeletonweed/) | Exact listing name. |
| Squarrose knapweed | *Centaurea virgata* | [Squarrose knapweed](https://denson.github.io/colorado-weed-field-guide/plants/squarrose-knapweed/) | Exact listing name. |
| Tansy ragwort | *Senecio jacobaea* | [Tansy ragwort](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Ventenata | *Ventenata dubia* | [Ventenata](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/) | Exact listing name. |
| Yellow flag iris | *Iris pseudacorus* | [Yellow flag iris](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/) | Exact listing name. |
| Yellow starthistle | *Centaurea solstitialis* | [Yellow starthistle](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/) | Exact listing name. |
## List B — Stop the spread · 37 entries
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread.
| State listing | Listed scientific name | Illustrated profile | Mapping and limits |
|---|---|---|---|
| Absinth wormwood | *Artemisia absinthium* | [Absinth wormwood](https://denson.github.io/colorado-weed-field-guide/plants/absinth-wormwood/) | Exact listing name. |
| Black henbane | *Hyoscyamus niger* | [Black henbane](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/) | Exact listing name. |
| Bouncingbet | *Saponaria officinalis* | [Bouncingbet](https://denson.github.io/colorado-weed-field-guide/plants/bouncingbet/) | Exact listing name. |
| Bull thistle | *Cirsium vulgare* | [Bull thistle](https://denson.github.io/colorado-weed-field-guide/plants/bull-thistle/) | Exact listing name. |
| Canada thistle | *Cirsium arvense* | [Canada thistle](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/) | Exact listing name. |
| Chinese clematis | *Clematis orientalis* | [Chinese clematis](https://denson.github.io/colorado-weed-field-guide/plants/chinese-clematis/) | Exact listing name. |
| Common tansy | *Tanacetum vulgare* | [Common tansy](https://denson.github.io/colorado-weed-field-guide/plants/common-tansy/) | Exact listing name. |
| Common teasel | *Dipsacus fullonum* | [Common teasel](https://denson.github.io/colorado-weed-field-guide/plants/common-teasel/) | Exact listing name. |
| Cutleaf teasel | *Dipsacus laciniatus* | [Cutleaf teasel](https://denson.github.io/colorado-weed-field-guide/plants/cutleaf-teasel/) | Exact listing name. |
| Dalmatian toadflax, broad-leaved | *Linaria dalmatica* | [Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/dalmatian-toadflax/) | Exact listing name. |
| Dalmatian toadflax, narrow-leaved | *Linaria genistifolia* | [Narrow-leaved Dalmatian toadflax](https://denson.github.io/colorado-weed-field-guide/plants/narrow-leaved-dalmatian-toadflax/) | Exact listing name. |
| Dame's rocket | *Hesperis matronalis* | [Dame’s rocket](https://denson.github.io/colorado-weed-field-guide/plants/dames-rocket/) | Exact listing name. |
| Diffuse knapweed | *Centaurea diffusa* | [Diffuse knapweed](https://denson.github.io/colorado-weed-field-guide/plants/diffuse-knapweed/) | Exact listing name. |
| Eurasian watermilfoil | *Myriophyllum spicatum* | [Eurasian watermilfoil](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/) | Exact listing name. |
| Hoary cress | *Lepidium draba* | [Hoary cress](https://denson.github.io/colorado-weed-field-guide/plants/hoary-cress/) | Exact listing name. |
| Houndstongue | *Cynoglossum officinale* | [Houndstongue](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/) | Exact listing name. |
| Jointed goatgrass | *Aegilops cylindrica* | [Jointed goatgrass](https://denson.github.io/colorado-weed-field-guide/plants/jointed-goatgrass/) | Exact listing name. |
| Leafy spurge | *Euphorbia esula* | [Leafy spurge](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/) | Exact listing name. |
| Mayweed/stinking chamomile | *Anthemis cotula* | [Mayweed chamomile](https://denson.github.io/colorado-weed-field-guide/plants/mayweed-chamomile/) | Exact listing name. |
| Moth mullein | *Verbascum blattaria* | [Moth mullein](https://denson.github.io/colorado-weed-field-guide/plants/moth-mullein/) | Exact listing name. |
| Musk thistle | *Carduus nutans* | [Musk thistle](https://denson.github.io/colorado-weed-field-guide/plants/musk-thistle/) | Exact listing name. |
| Oxeye daisy | *Leucanthemum vulgare* | [Oxeye daisy](https://denson.github.io/colorado-weed-field-guide/plants/oxeye-daisy/) | Exact listing name. |
| Perennial pepperweed | *Lepidium latifolium* | [Perennial pepperweed](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/) | Exact listing name. |
| Plumeless thistle | *Carduus acanthoides* | [Plumeless thistle](https://denson.github.io/colorado-weed-field-guide/plants/plumeless-thistle/) | Exact listing name. |
| Russian knapweed | *Rhaponticum repens* | [Russian knapweed](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/) | Exact listing name. |
| Russian-olive | *Elaeagnus angustifolia* | [Russian olive](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/) | Exact listing name. |
| Salt cedar | *Tamarix chinensis and T. ramosissima* | [Tamarisk](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/) | One state listing covers T. chinensis and T. ramosissima. The profile discusses the saltcedar group; photographs are source-identified T. ramosissima and do not separately resolve T. chinensis or hybrids. |
| Scentless chamomile | *Tripleurospermum inodorum* | [Scentless chamomile](https://denson.github.io/colorado-weed-field-guide/plants/scentless-chamomile/) | Exact listing name. |
| Scotch thistle | *Onopordum acanthium* | [Scotch thistle](https://denson.github.io/colorado-weed-field-guide/plants/scotch-thistle/) | Exact listing name. |
| Scotch thistle | *Onopordum tauricum* | [Taurian thistle](https://denson.github.io/colorado-weed-field-guide/plants/taurian-thistle/) | Exact listing name. |
| Spotted knapweed | *Centaurea stoebe ssp.micranthos* | [Spotted knapweed](https://denson.github.io/colorado-weed-field-guide/plants/spotted-knapweed/) | The state names ssp. micranthos; the illustrated profile uses C. stoebe broadly and does not independently verify chromosome/subspecies identity. |
| Spotted x diffuse knapweed hybrid | *Centaurea x psammogena* | [Spotted × diffuse knapweed hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-knapweed/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
| Sulfur cinquefoil | *Potentilla recta* | [Sulfur cinquefoil](https://denson.github.io/colorado-weed-field-guide/plants/sulfur-cinquefoil/) | Exact listing name. |
| Wild caraway | *Carum carvi* | [Wild caraway](https://denson.github.io/colorado-weed-field-guide/plants/wild-caraway/) | Exact listing name. |
| Yellow nutsedge | *Cyperus esculentus* | [Yellow nutsedge](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/) | Exact listing name. |
| Yellow toadflax | *Linaria vulgaris* | [Yellow toadflax](https://denson.github.io/colorado-weed-field-guide/plants/yellow-toadflax/) | Exact listing name. |
| Yellow x Dalmatian toadflax hybrid | *Linaria vulgaris x L. dalmatica* | [Yellow × Dalmatian toadflax hybrid](https://denson.github.io/colorado-weed-field-guide/plants/hybrid-toadflax/) | Synonym, spelling or taxon-scope mapping; see profile caveat. |
## List C — Manage widespread weeds · 18 entries
Widespread and well established. Control is recommended by the state; local governments may require management.
| State listing | Listed scientific name | Illustrated profile | Mapping and limits |
|---|---|---|---|
| Bulbous bluegrass | *Poa bulbosa* | [Bulbous bluegrass](https://denson.github.io/colorado-weed-field-guide/plants/bulbous-bluegrass/) | Exact listing name. |
| Chicory | *Cichorium intybus* | [Chicory](https://denson.github.io/colorado-weed-field-guide/plants/chicory/) | Exact listing name. |
| Common burdock | *Arctium minus* | [Common burdock](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/) | Exact listing name. |
| Common mullein | *Verbascum thapsus* | [Common mullein](https://denson.github.io/colorado-weed-field-guide/plants/common-mullein/) | Exact listing name. |
| Common St. Johnswort | *Hypericum perforatum* | [Common St. Johnswort](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/) | Exact listing name. |
| Downy brome | *Bromus tectorum* | [Cheatgrass / downy brome](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/) | Exact listing name. |
| Field bindweed | *Convolvulus arvensis* | [Field bindweed](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/) | Exact listing name. |
| Halogeton | *Halogeton glomeratus* | [Halogeton](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/) | Exact listing name. |
| Johnsongrass | *Sorghum halepense* | [Johnsongrass](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/) | Exact listing name. |
| Perennial sowthistle | *Sonchus arvensis* | [Perennial sowthistle](https://denson.github.io/colorado-weed-field-guide/plants/perennial-sowthistle/) | Exact listing name. |
| Poison hemlock | *Conium maculatum* | [Poison hemlock](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/) | Exact listing name. |
| Puncturevine | *Tribulus terrestris* | [Puncturevine / goathead](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/) | Exact listing name. |
| Quackgrass | *Elymus repens* | [Quackgrass](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/) | Exact listing name. |
| Redstem filaree | *Erodium cicutarium* | [Redstem filaree](https://denson.github.io/colorado-weed-field-guide/plants/redstem-filaree/) | Exact listing name. |
| Siberian elm | *Ulmus pumila* | [Siberian elm](https://denson.github.io/colorado-weed-field-guide/plants/siberian-elm/) | Exact listing name. |
| Tree of heaven | *Ailanthus altissima* | [Tree of heaven](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/) | Exact listing name. |
| Velvetleaf | *Abutilon theophrasti* | [Velvetleaf](https://denson.github.io/colorado-weed-field-guide/plants/velvetleaf/) | Exact listing name. |
| Wild proso millet | *Panicum miliaceum* | [Wild proso millet](https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/) | Exact listing name. |
## Still open
- County-by-county occurrence and abundance are not mapped.
- Common and native weeds beyond this catalog remain to be added; this is not the entire Colorado flora.
- Some species complexes, subspecies and hybrids need expert verification; image identity follows the credited source.
- Species-specific pet toxicology is missing for many plants and is labeled in each profile.
- One hybrid-toadflax flower photograph is only 176 by 329 pixels.
- The wild-violet genus is represented by one species, and several manufacturer topics combine species still missing from this guide. The comparison is a research backlog, not evidence that every missing plant occurs in Colorado.
# Appendix for agents
Use [coverage.json](https://denson.github.io/colorado-weed-field-guide/coverage.json) for the row-to-profile mapping. Preserve listed_taxon separately from profile_taxon; an exact spelling match is not a new botanical determination. Do not infer county occurrence from regulatory listing or a photograph taken elsewhere.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/coverage/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/coverage/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/coverage/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/biggest-concerns/index.md
---
{
"source_ids": [
"A-greasewood",
"A-halogeton",
"A-larkspur",
"A-loco",
"A-ragwort",
"ARS-deathcamas",
"ARS-larkspur",
"B-deathcamas",
"C-descriptions",
"C-floristic-2020",
"C-foxtail",
"C-low-water-cactus",
"C-ragweed-native",
"C-routt-guide",
"C-tumbleweeds",
"C-wetland-guide",
"CO-rules-2025",
"F-ambrosia-psilostachya",
"F-apocynum",
"F-gutierrezia",
"F-locoweed",
"F-melilotus",
"F-opuntia",
"F-sarcobatus",
"F-securigera",
"F-sisymbrium",
"F-urtica",
"FDA-poison-ivy",
"Fremont-list-definitions",
"I-buffalobur",
"I-giant-ragweed",
"J-canada-thistle",
"J-houndstongue",
"J-leafy-spurge",
"J-perennial-pepperweed",
"J-russian-knapweed",
"J-russian-olive",
"J-saltcedar---tamarisk",
"K-bindweed",
"K-kochia",
"M-quackgrass",
"N-ailanthus-altissima",
"N-amaranthus-retroflexus",
"N-ambrosia-artemisiifolia",
"N-apocynum-cannabinum",
"N-arctium-minus",
"N-arundo-donax",
"N-centaurea-solstitialis",
"N-convolvulus-arvensis",
"N-cyperus-esculentus",
"N-datura-stramonium",
"N-erigeron-canadensis",
"N-euphorbia-cyparissias",
"N-euphorbia-esula",
"N-euphorbia-maculata",
"N-euphorbia-marginata",
"N-galium-aparine",
"N-hydrilla-verticillata",
"N-hyoscyamus-niger",
"N-hypericum-perforatum",
"N-iris-pseudacorus",
"N-lythrum-salicaria",
"N-melilotus-officinalis",
"N-myriophyllum-aquaticum",
"N-myriophyllum-spicatum",
"N-pastinaca-sativa",
"N-ranunculus-acris",
"N-reynoutria-japonica",
"N-rhaponticum-repens",
"N-salvinia-molesta",
"N-securigera-varia",
"N-solanum-dulcamara",
"N-sorghum-halepense",
"N-urtica-dioica",
"N-xanthium-strumarium",
"NPS-african",
"P-buttercup",
"P-dogbane",
"S04",
"S05",
"S06",
"S13",
"S14",
"S15",
"S16",
"S17",
"S18",
"S19",
"S20",
"S21",
"S22",
"S26",
"S27",
"S29",
"U-buffalobur",
"U-silverleaf",
"U-water-hemlock",
"UC-russian-thistle",
"W-buffalobur",
"WA-african-rue",
"WA-bohemian-knotweed",
"WA-flowering-rush",
"WA-medusahead",
"WA-tansy-ragwort",
"WA-ventenata"
]
}
---
# Biggest concerns
Start with the kind of problem you need to prevent. These are selected routes into the guide, not a universal severity ranking. Read each profile for the affected animal group and evidence limits. For suspected exposure, use the [safety guide](https://denson.github.io/colorado-weed-field-guide/safety/).
State-list labels describe management requirements, separately from these hazards. [What Lists A, B and C mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).
## Serious ingestion hazards
Plants with serious poisoning warnings. Affected species and evidence strength differ; use the individual profile before drawing conclusions about a person or animal.
- [Poison hemlock](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/) — **Poisonous to people & animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/poison-hemlock/).
- [Western water hemlock](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/) — **Potentially fatal poisoning; wetland look-alike danger**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/index.md).
 Photo: Lee Cain; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-water-hemlock/).
- [Jimsonweed](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/) — **Serious poisoning risk to people and animals**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/jimsonweed/).
- [Black henbane](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/) — **Highly poisonous; keep animals away**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-henbane/).
- [Meadow death camas](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/) — **Potentially fatal ingestion; onion-like bulbs**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/index.md).
 Photo: NPS Photo; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/meadow-death-camas/).
- [African rue](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/) — **Highly poisonous if eaten; deep-rooted invader**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/index.md).
 Photo: Alex Abair; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/african-rue/).
- [Bittersweet nightshade](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/) — **Poisonous berries and foliage**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bittersweet-nightshade/).
- [Western whorled milkweed](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/) — **High livestock toxicity**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/index.md).
 Photo: Patrick Alexander from Las Cruces, NM; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-whorled-milkweed/).
- [Hemp dogbane](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/) — **Cardiac-glycoside poisoning hazard for people and animals**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hemp-dogbane/).
- [Silverleaf nightshade](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/) — **Toxic leaves and berries; persistent spreading roots**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md).
 Photo: Sam Kieschnick; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/).
- [Tall buttercup](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/) — **Fresh plant irritation and animal poisoning hazard**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/index.md).
 Photo: Daniel Cahen; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-buttercup/).
- [Crownvetch](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/) — **Toxic to horses; spreading roots can smother vegetation**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md).
 Photo: Dale Knox; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/).
## Pets, paws and skin contact
A route to awns, burs, sharp points and irritating plant contact, including poison-ivy oil carried on fur.
- [Foxtail barley](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/) — **Barbed seed awns injure animals**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/index.md).
 Photo: Diego Delso; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/foxtail-barley/).
- [Puncturevine / goathead](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/) — **Sharp burs · Animal injury**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/index.md).
 Photo: Forest & Kim Starr; CC BY 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/puncturevine/).
- [Common burdock](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/) — **Burs and fine bristles injure animals**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-burdock/).
- [Common cocklebur](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/) — **Burs catch in fur; seedlings and seeds are hazardous**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/index.md).
 Photo: Franco Folini; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-cocklebur/).
- [Myrtle spurge](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/) — **Poisonous · Eye & skin injury**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/index.md).
 Photo: Flocci Nivis; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/myrtle-spurge/).
- [Cypress spurge](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/) — **Sap can injure skin and eyes**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/index.md).
 Photo: Tom Scavo; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cypress-spurge/).
- [Western poison ivy](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/) — **Skin-rash oil can travel on pet fur**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/index.md).
 Photo: Andrey Zharkikh from Salt Lake City, USA; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-poison-ivy/).
- [Buffalobur](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/) — **Sharp spines; toxic to livestock**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/index.md).
 Photo: Juan Carlos Fonseca Mata; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/buffalobur/).
- [Wild parsnip](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/) — **Sap plus sunlight can cause severe skin burns**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/wild-parsnip/).
- [Stinging nettle](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/) — **Stinging hairs; this profile covers a taxonomic complex**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/index.md).
 Photo: Przykuta; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/stinging-nettle/).
- [Spotted spurge](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/) — **Milky sap can injure skin and eyes; keep pets from chewing**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/spotted-spurge/).
- [Snow-on-the-mountain](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/) — **Latex can damage skin and eyes; toxic if eaten**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/index.md).
 Photo: Mark G; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/snow-on-the-mountain/).
- [Plains pricklypear](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/) — **Sharp spines around paws, mouths and eyes**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/index.md).
 Photo: eigenmotion; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/plains-pricklypear/).
- [Catchweed bedstraw](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/) — **Hooked hairs and burrs cling to fur and clothing**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/catchweed-bedstraw/).
## Pasture, hay and livestock losses
For landowners and animal keepers: forage poisoning and injury deserve their own review. Livestock findings are not pet exposure limits.
- [Tall larkspur](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/) — **Serious livestock and pet poisoning hazard**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/index.md).
 Photo: Ms. Sticky; CC BY 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/).
- [Low larkspur](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/) — **Serious livestock and pet poisoning hazard**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/index.md).
 Photo: NPS; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/low-larkspur/).
- [Halogeton](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/) — **Severe oxalate poisoning in livestock**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/halogeton/).
- [Johnsongrass](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/) — **Livestock cyanide risk; added fire fuel**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/index.md).
 Photo: Jim Conrad; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/johnsongrass/).
- [Tansy ragwort](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/) — **Poisonous to livestock; harmful alkaloids**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/index.md).
 Photo: jamie-aa; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tansy-ragwort/).
- [Russian knapweed](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/) — **Toxic to horses**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/index.md).
 Photo: Amirh. absnd; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-knapweed/).
- [Yellow starthistle](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/) — **Severe horse poisoning; sharp spines**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/index.md).
 Photo: Юрий Данилевский (Yuriy Danilevsky); CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-starthistle/).
- [Houndstongue](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/) — **Toxic to livestock**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/index.md).
 Photo: Bernd Haynold; CC BY 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/houndstongue/).
- [White locoweed](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/) — **Toxic to livestock**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-locoweed/).
- [Kochia](https://denson.github.io/colorado-weed-field-guide/plants/kochia/) — **Tumbling seed spread; livestock poisoning risk**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/kochia/index.md).
 Photo: WildBoar; Public domain. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/kochia/).
- [Redroot pigweed](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/) — **Crop competition; nitrate and oxalate livestock risk**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/index.md).
 Photo: Lynk media; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/redroot-pigweed/).
- [Common St. Johnswort](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/) — **Photosensitivity and animal exposure concerns**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/index.md).
 Photo: W. Bulach; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-st-johnswort/).
- [Broom snakeweed](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/) — **Livestock poisoning and abortion risk when heavily eaten**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/index.md).
 Photo: CK2AZ; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/broom-snakeweed/).
- [Black greasewood](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/) — **Oxalate poisoning can be fatal to livestock**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/index.md).
 Photo: John Gaskin; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/).
- [Yellow sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/) — **Moldy sweetclover hay can cause dangerous bleeding**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/index.md).
 Photo: Isidre blanc; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-sweetclover/).
- [White sweetclover](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/) — **Moldy sweetclover hay can cause dangerous bleeding**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/white-sweetclover/).
- [Crownvetch](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/) — **Toxic to horses; spreading roots can smother vegetation**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md).
 Photo: Dale Knox; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/).
## Dry grass, tumbleweeds and fire concerns
Read the profiles for the evidence about dry vegetation, tumbling plants and effects on land management.
- [Cheatgrass / downy brome](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/) — **Grass awns · Fire hazard**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/index.md).
 Photo: AnRo0002; CC0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/cheatgrass/).
- [Medusahead](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/) — **Barbed awns; persistent fire-promoting thatch**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/index.md).
 Photo: Matt Lavin from Bozeman, Montana, USA; CC BY-SA 2.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/medusahead/).
- [Ventenata](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/) — **Displaces forage and native grassland**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/index.md).
 Photo: Matt Lavin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/ventenata/).
- [Russian thistle](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/) — **Prickly tumbleweeds; livestock and fire hazards**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/index.md).
 Photo: Stefan.lefnaer; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/).
- [Tumble mustard](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/) — **Another tumbleweed: brittle plants scatter persistent seed**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/index.md).
 Photo: Ben Keen; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tumble-mustard/).
## Persistent roots and habitat displacement
Plants whose spread or persistence can make restoration and routine garden management difficult. Methods depend on the site and confirmed identity.
- [Field bindweed](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/) — **Smothers plants; livestock concern**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/index.md).
 Photo: Svklimkin; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/field-bindweed/).
- [Canada thistle](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/) — **Sharp spines; competes with vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/index.md).
 Photo: Ivar Leidus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/canada-thistle/).
- [Leafy spurge](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/) — **Irritating sap; eye injury risk**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/index.md).
 Photo: H. Zell; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/leafy-spurge/).
- [Japanese knotweed](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/) — **Root and stem fragments regrow**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/index.md).
 Photo: Michael Gasperl ( Migas ); CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/japanese-knotweed/).
- [Bohemian knotweed](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/) — **Hybrid regrows from small fragments**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/index.md).
 Photo: Patrick Hacker; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/bohemian-knotweed/).
- [Perennial pepperweed](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/) — **Deep roots form persistent wetland colonies**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/perennial-pepperweed/).
- [Tree of heaven](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/) — **Root suckers form persistent thickets**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/index.md).
 Photo: Darkone; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tree-of-heaven/).
- [Russian olive](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/) — **Thorns; riparian habitat concern**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/index.md).
 Photo: Georg Slickers; CC BY-SA 2.5. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/russian-olive/).
- [Tamarisk](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/) — **Alters riparian vegetation**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/index.md).
 Photo: Jerzy Opioła; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/tamarisk/).
- [Yellow nutsedge](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/) — **Underground tubers sustain infestations**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/index.md).
 Photo: Krzysztof Ziarnek, Kenraiz; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-nutsedge/).
- [Quackgrass](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/) — **Rhizome fragments regrow in lawns and gardens**. State management: [List C — Manage widespread weeds](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/index.md).
 Photo: Rasbak; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/quackgrass/).
- [Giant reed](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/) — **Dense stands displace riparian plants**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/index.md).
 Photo: zebedeugalinha; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-reed/).
- [Horseweed](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/) — **Fast windborne spread; some populations resist herbicides**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/index.md).
 Photo: Enrico Blasutto; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/horseweed/).
- [Silverleaf nightshade](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/) — **Toxic leaves and berries; persistent spreading roots**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/index.md).
 Photo: Sam Kieschnick; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/silverleaf-nightshade/).
- [Crownvetch](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/) — **Toxic to horses; spreading roots can smother vegetation**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/index.md).
 Photo: Dale Knox; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/crownvetch/).
## Waterways and aquatic habitats
Use the individual accounts to understand spread and identification before moving plants, water or equipment from an affected site.
- [Hydrilla](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/) — **Dense aquatic growth; wildlife disease association**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/index.md).
 Photo: Stanislav Murashkin; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/hydrilla/).
- [Giant salvinia](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/) — **Floating mats harm aquatic habitat**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/index.md).
 Photo: Ixitixel; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-salvinia/).
- [Eurasian watermilfoil](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/) — **Fragments spread dense aquatic growth**. State management: [List B — Stop the spread](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/index.md).
 Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org; CC BY 3.0 us. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/eurasian-watermilfoil/).
- [Parrotfeather](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/) — **Aquatic mats obstruct waterways**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/index.md).
 Photo: Quillipede; CC0 1.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/parrotfeather/).
- [Flowering rush](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/) — **Small fragments spread aquatic colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/index.md).
 Photo: Jacek Pietruszewski; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/flowering-rush/).
- [Purple loosestrife](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/) — **Crowds out wetland vegetation**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/index.md).
 Photo: Douglas Goldman; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/purple-loosestrife/).
- [Yellow flag iris](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/) — **Ingestion concern; invasive wetland colonies**. State management: [List A — Eradicate](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists). [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/index.md).
 Photo: Kailey Alderfer; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/yellow-flag-iris/).
## Pollen and seasonal allergies
Ragweed profiles separate documented allergy concerns from species-specific questions still under research. This is not a local pollen forecast.
- [Common ragweed](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/) — **Pollen allergy; skin irritation**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/index.md).
 Photo: Ayotte, Gilles, 1948-; CC BY-SA 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/common-ragweed/).
- [Giant ragweed](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/) — **Allergenic pollen and strong competition in disturbed ground**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/index.md).
 Photo: GTBacchus; CC BY-SA 3.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/giant-ragweed/).
- [Western ragweed](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/) — **A persistent perennial ragweed; allergy detail still under review**. [Evidence and agent notes](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/index.md).
 Photo: Zihao Wang; CC BY 4.0. [Photo credits and sources](https://denson.github.io/colorado-weed-field-guide/plants/western-ragweed/).
## Early detection matters
All **List A — Eradicate** entries are included in the [coverage checklist](https://denson.github.io/colorado-weed-field-guide/coverage/). Statewide eradication requirements make these reporting priorities even where a plant is not yet widespread. [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2).
# Appendix for agents
Group membership is an editorial selection based on the linked profile warnings. It is not an incidence estimate, dose comparison or complete toxic-plant list. The [concerns.json](https://denson.github.io/colorado-weed-field-guide/concerns.json) mapping preserves these choices; claim-level references remain with each plant.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/biggest-concerns/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/biggest-concerns/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/biggest-concerns/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/about/index.md
---
{
"id": "about",
"title": "About this guide",
"source_ids": [
"S01",
"S27",
"ST-pattern"
],
"description": "About this guide for the Colorado Plants & Practical Care",
"source": "content/pages/about.md"
}
---
# About this guide
Every plant page is labeled **Still researching this plant**, with visible evidence gaps and open questions in its agent notes. This allows useful, sourced working profiles to be published while uncertain taxonomy, pet effects and expert review remain explicit.
This independent guide covers **154 plant profiles** relevant to Colorado yards, gardens, paths and disturbed land. It separates native volunteers, xeriscape spreaders and invasive and common weeds, while giving each plant dedicated sections for people, dogs and cats, other animals, and surrounding vegetation.
“Weed” describes a plant growing where someone does not want it. It does not erase that plant’s ecological value. Colorado native communities also differ across elevation, exposure and climate. A garden choice for one site may not fit another. [CSU Extension: Native Plants](https://extension.colostate.edu/resource/native-plants/).
The [coverage checklist](https://denson.github.io/colorado-weed-field-guide/coverage/) maps all **82 entries** in Colorado’s reviewed A, B and C lists to illustrated profiles. Additional profiles cover common weeds, native hazards and xeriscape spreaders. [Biggest concerns](https://denson.github.io/colorado-weed-field-guide/biggest-concerns/) offers a practical starting point. Coverage of a listing includes documented taxonomic limits; it is not a claim that every subspecies or hybrid has been independently confirmed.
## How the evidence is handled
Profiles are AI-assisted editorial syntheses of linked Extension, government, poison-control and veterinary sources. **Independent botanical and veterinary expert review is pending.** This is a selected catalog, not a complete flora, poison database or identification key.
Each factual section links its sources. The additional Markdown notes distinguish species-level findings, genus-level evidence, animal-group evidence, physical-risk inferences and unresolved questions. Source publication dates, retrieval dates and page revision times are kept separate.
Every plant has three distinct, source-identified photographs. Photographer credits and licenses appear beside the photos. We do not claim a photograph was taken in Colorado unless its source documents that location. Images are reference examples, not independent determinations of a visitor’s plant.
## Built for people and their assistants
The site follows the published [Stoagen pattern](https://stoagen.com/pattern/index.md): readable static pages, a Markdown mirror with additional evidence notes, and visible links for agents. This is an independent implementation. All substantive profile content is available without JavaScript or a sign-in.
The source project lives in [GitHub](https://github.com/denson/colorado-weed-field-guide). Ordinary HTML, Markdown, JSON, CSS and image files can be served by another static host. No OpenAI hosting runtime is required.
## Corrections and reuse
Propose a correction through the [GitHub repository](https://github.com/denson/colorado-weed-field-guide), including the scientific name, the claim in question and a supporting source. Source errors, taxonomic changes and new toxicology evidence should be recorded explicitly.
Photo licenses apply individually and are linked with each image. Third-party publications retain their own copyrights; this site paraphrases their facts and links to the originals. No blanket license over those sources or photographs is claimed.
# Appendix for agents
## Editorial record
The first prototype contained 10 plants. The first portable edition expanded to 40 profiles with three photographs each and replaced the hosted application with a portable static build. The next edition reached 119 profiles and 357 photographs. The current expansion has 154 profiles and 462 photographs, with every entry in the reviewed A/B/C lists mapped and additional common weeds and native hazards. Profile prose is maintained in Markdown. Provenance records retain the earlier evidence used and document exclusions for common-name mismatches.
Authorship is AI-assisted, for the project owner. Source organizations and photographers are not represented as endorsing this guide. Content revision dates are generated from recorded source revisions and source-file hashes; they are not dates of scientific validation or promises of monitoring.
## Limits
Category membership is navigation. Some native plants also belong in xeriscape gardens. Current legal obligations depend on location; no county instruction is silently generalized to all Colorado. No editorial risk inference asserts allelopathy, clinical toxicity, a safe dose or a measured restoration benefit without evidence.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/about/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/about/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/about/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/agents/index.md
---
{
"id": "agents",
"title": "Read this guide with an AI assistant",
"source_ids": [
"ST-pattern"
],
"description": "Read this guide with an AI assistant for the Colorado Plants & Practical Care",
"source": "content/pages/agents.md"
}
---
# Read this guide with an AI assistant
Use the Markdown profile when you need the full article plus detailed evidence notes. The text fallback contains identical bytes for tools that do not accept Markdown responses.
- Short entry: [https://denson.github.io/colorado-weed-field-guide/start.md](https://denson.github.io/colorado-weed-field-guide/start.md)
- Page index: [https://denson.github.io/colorado-weed-field-guide/llms.txt](https://denson.github.io/colorado-weed-field-guide/llms.txt)
- Full corpus: [https://denson.github.io/colorado-weed-field-guide/llms-full.txt](https://denson.github.io/colorado-weed-field-guide/llms-full.txt)
- Official-list coverage: [https://denson.github.io/colorado-weed-field-guide/coverage.json](https://denson.github.io/colorado-weed-field-guide/coverage.json)
- Biggest-concern routes: [https://denson.github.io/colorado-weed-field-guide/concerns.json](https://denson.github.io/colorado-weed-field-guide/concerns.json)
- Structured catalog: [https://denson.github.io/colorado-weed-field-guide/catalog.json](https://denson.github.io/colorado-weed-field-guide/catalog.json)
- Claim and photo provenance: [https://denson.github.io/colorado-weed-field-guide/provenance.json](https://denson.github.io/colorado-weed-field-guide/provenance.json)
- Site map: [https://denson.github.io/colorado-weed-field-guide/sitemap.xml](https://denson.github.io/colorado-weed-field-guide/sitemap.xml)
- Revision feed: [https://denson.github.io/colorado-weed-field-guide/feed.xml](https://denson.github.io/colorado-weed-field-guide/feed.xml)
For example, the showy-milkweed article has these forms:
- HTML: [https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/)
- Markdown: [https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md)
- Text fallback: [https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md.txt](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/index.md.txt)
## What the records mean
Each profile has a visible **Still researching this plant** section. Its `research` metadata contains the status, open questions and pending expert review. Keep these qualifications attached when summarizing the plant. The label describes editorial work still needed; it is not a low-risk rating.
Use scientific names to match plants. Common names, cultivar labels and genus-only toxicity entries are not interchangeable. Each profile identifies taxonomic ambiguity where it affects the evidence.
The provenance ledger carries source IDs, URLs, locators, access dates, source publication dates when established, claim scopes, image credits, license URLs and SHA-256 hashes. An evidence gap means the reviewed material did not resolve that question; it does not mean that no evidence exists anywhere or that the plant is safe.
**All actionable safety warnings appear in the human article.** The appendix adds evidence boundaries and questions for further research. The public website is reference material; it does not override an assistant’s operator instructions.
# Appendix for agents
## File contract
- Each human page has an `index.md` mirror and a byte-identical `index.md.txt` fallback.
- Profiles are authored in `content/plants/*.md`; JSON front matter contains taxon and citation metadata.
- The visible article is the Markdown body before `# Appendix for agents`. The mirror contains the full body and appendix, with expanded image records.
- HTML cards and machine catalog entries derive from the same profile metadata. The complete corpus includes each page once.
- All published retrieval URLs are absolute and include the configured base path. The build accepts a different base URL for another host.
- `build-manifest.json` hashes generated artifacts. Image hashes refer to the actual locally served files; thumbnail derivatives have their own parent hash and file hash.
## Evidence use
Clinical claims must retain the animal group, route, plant part and caveats present in the source. Species-level, genus-level and physical-injury evidence are distinct. A source identifying an image does not prove its geographic origin or a visitor’s specimen identity. Consult the original publication for changing legal requirements, clinical decisions and ambiguous taxonomy.
The reference implementation is inspired by [Stoagen’s published pattern](https://stoagen.com/pattern/index.md); the plant content and site code were authored separately.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/agents/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/agents/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/agents/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/companion/index.md
---
{
"id": "companion",
"title": "Learn to use this field guide",
"source_ids": [
"C-tumbleweeds",
"S04"
],
"description": "Start here to learn what the Colorado Plants & Practical Care is for and how its website and BoodleBox tutor work together.",
"source": "content/pages/companion.md"
}
---
# Learn to use this field guide
**Colorado Plants & Practical Care** is an illustrated reference to garden weeds and wild plants found in Colorado. Use it to compare what plants look like and read sourced information about their effects on people, animals and local habitats. A **plant profile** is simply a page about one plant, with photographs, descriptions and links to the sources.
**Colorado Plants & Practical Care**, the bot in BoodleBox, is your tutor for using this website. It explains where to click, what the page sections mean and how to discuss what you read. You can learn the site without knowing any plant names or having a plant to identify.
## Meet the two examples
We will visit Russian thistle first, then showy milkweed. These are reference examples for learning the site; you do not need either plant in your yard.
### 1. Russian thistle: recognize a tumbleweed
Photo: Stefan.lefnaer; CC BY-SA 3.0.
A widespread introduced weed that dries into a tumbleweed. We will use our Russian thistle page to practice searching, compare the photographs with Recognize, and read Plants & habitat to learn how it spreads.
### 2. Showy milkweed: check pet hazards
Photo: Andrey Zharkikh; CC BY 2.0.
Its pink flowers make an appealing second example. Our Showy milkweed page has a Dogs & cats section explaining the pet warning and its limits. Milkweeds are toxic to dogs and cats; the warning covers milkweeds as a group. The original ASPCA reference is available on that plant page.
Read more in our guide: [Russian thistle](https://denson.github.io/colorado-weed-field-guide/plants/russian-thistle/) · [Showy milkweed](https://denson.github.io/colorado-weed-field-guide/plants/showy-milkweed/). Each plant page includes the evidence, original references and full photo credits.
## Now open the plant library
**[Open the plant library](https://denson.github.io/colorado-weed-field-guide/)**, then tell the bot **ready**. Keep using the same BoodleBox conversation. If you have not opened the tutor yet, [open Colorado Plants & Practical Care](https://box.boodle.ai/a/@ColoradoWeedGuide) and choose **Start New Chat**.
The tutor will guide you through these steps, one at a time:
1. **Find a familiar weed.** Search for **Russian thistle**, a widespread tumbleweed. Use its photographs and the **Recognize** and **Plants & habitat** sections to learn what a plant page can tell you.
2. **Check a flower’s pet warning.** Next, search for **showy milkweed**. Read **Dogs & cats** on its plant page to understand the warning and its evidence. Original sources are there if you want more detail; opening them is optional.
3. **Discuss what you learned.** Later, return here to prepare a short practice message called a **note**. Put it in BoodleBox, review it and press **Send**. The tutor can then discuss your takeaway or answer your question.
Start with the library; the note form below is for that later step. Selecting a reference plant is not a confirmed identification of a plant outdoors.
Open the [interactive field-note form](https://denson.github.io/colorado-weed-field-guide/companion/) or the [Colorado Plants & Practical Care bot](https://box.boodle.ai/a/@ColoradoWeedGuide). Start by learning what the website is for and opening its plant library. The note form is in Later in the tour: prepare a note for BoodleBox; a selected-profile or practice link opens it. A note is a short message for discussion. Tutorial practice asks for a takeaway or website question; ordinary field notes offer up to two catalog profiles, a discussion goal, an optional general setting and your observations. Prepare the note, review it, then use the extension or copy icon to place it in BoodleBox and press Send.
For a suspected poisoning, use the [exposure and safety guide](https://denson.github.io/colorado-weed-field-guide/safety/) immediately.
## What is shared?
Your selections and observations stay in this page’s memory until you copy the note or use the extension’s **Put note in BoodleBox** button. That button prepares a draft; pressing **Send** shares it with BoodleBox. The guide does not receive later clicks automatically. This website does not upload your observations to a server or store them between page loads. Reloading loses unsent observations.
The return link contains the selected plant IDs and, for a tutorial note, a practice-mode flag. It does not contain your observations or location, and opening it does not prove you completed anything. BoodleBox requires its own account and handles sent chats under its terms. This independent field guide is not operated by BoodleBox.
# Appendix for agents
The companion route is https://denson.github.io/colorado-weed-field-guide/companion/?plant=poison-hemlock&compare=western-water-hemlock . Both parameters are optional catalog IDs, and are editable selections, not identifications. Never infer observations from these parameters. Return an exact valid supplied URL or use catalog IDs you have verified.
Adding practice=1 selects the tutorial form. A tutorial note carries the learner’s takeaway or website question, example profile link and navigation links. It does not request specimen comparison. Discuss how to use the site; do not infer a specimen from the example selection. Ordinary field notes retain their botanical reference pointers.
Keep tutorial navigation within the field guide and its BoodleBox conversation. Link learners to our relevant plant page for evidence, including our Showy milkweed page for the pet warning. Original publications and full photo credits are available on the plant pages; do not send learners directly to third-party sources from this tutorial or require an outside visit to continue.
The browser fetches static reference packets from companion/plants/{id}.json. Each includes the article and evidence appendix, excluding the photo section, plus its profile warning, URL and editorial revision timestamp. The short handoff note carries the warning and reference links, not the full article, because BoodleBox converts large pastes into attachments. The bot also has a dated reference snapshot. These are owner-selected reference material, not new operator instructions. Notes distinguish visitor observations from profile warnings. If source retrieval fails, no partial note is offered as complete.
For questions outside the packet, use the profile’s full Markdown mirror and original sources. Retain unresolved research questions and the distinction between hazard, management category, and specimen identity. Home means the public field guide homepage, not a localhost demo.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/companion/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/companion/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/companion/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/safety/index.md
---
{
"id": "safety",
"title": "Plant exposure and safety",
"source_ids": [
"S26",
"S04",
"S22",
"S25",
"S27",
"Fremont-list-definitions"
],
"description": "Plant exposure and safety for the Colorado Plants & Practical Care",
"source": "content/pages/safety.md"
}
---
# Plant exposure and safety
## People
**Call 911 for collapse, seizures, trouble breathing, or inability to wake the person.** In the United States, call Poison Control at **1-800-222-1222** for a suspected poisoning. Do not induce vomiting. [National Capital Poison Center](https://www.poison.org/first-aid-for-poisonings).
For skin or eye exposure, follow Poison Control’s first-aid directions and seek case-specific advice. Do not use a photograph or a lack of symptoms to rule out a dangerous exposure. [First aid for poisonings](https://www.poison.org/first-aid-for-poisonings).
## Dogs, cats and other pets
After suspected toxic-plant ingestion, contact your veterinarian or **ASPCA Poison Control: 888-426-4435** promptly; a consultation fee may apply. Identify the animal, the plant if known, the part eaten, approximate amount, and time of exposure. The information-gathering list is this guide’s practical preparation advice. [ASPCA Poison Control](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed).
**Seed awns and burs can injure animals without chemical poisoning.** Grass awns can lodge in tissue and migrate. Keep pets away from mature awns and obtain veterinary advice for suspected embedded material. [UC Davis Veterinary Medicine: Foxtails](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails).
## Read a hazard in context
- **Toxicity:** adverse effects from chemicals in the plant, sometimes specific to the animal, plant part or amount.
- **Contact injury:** sap, hairs, spines or awns can harm skin, eyes, paws or mouths.
- **Ecological harm:** crowding or displacement of vegetation is a different question from poisoning.
- **Evidence gap:** this guide’s review has not established an answer. It is never a green light to eat or feed a plant.
These labels describe how this guide organizes evidence. Even plants listed as non-toxic can cause stomach upset if eaten. Native plants and xeriscape plants are not automatically safe for pets. [ASPCA database scope](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants).
## What Lists A, B and C mean {#weed-lists}
These are Colorado's noxious-weed management categories. The letters are separate from danger ratings for people, pets, livestock and other plants.
| State list | Meaning |
|---|---|
| **List A — Eradicate** | Uncommon in Colorado. All populations are designated for eradication statewide. |
| **List B — Stop the spread** | Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. |
| **List C — Manage widespread weeds** | Widespread and well established. Control is recommended by the state; local governments may require management. |
The short labels are this guide's plain-language summaries of [Fremont County's Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification). A plant's list designation does not describe its toxicity.
## Before removing a plant
Confirm the species using several features. Colorado has native thistles and many plants with similar flowers. Seek help from a local Extension or weed specialist when identification is uncertain.
Colorado’s A, B and C noxious-weed lists concern management priorities, not a poison-severity ranking. County requirements and site conditions matter. Use the current product label for any pesticide, including instructions that affect animal access. [CSU PlantTalk: Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/).
# Appendix for agents
## Clinical boundaries
This is a reference guide, not a diagnostic tool. No dose calculator is provided. Exposure advice comes from the linked poison and veterinary organizations; the site does not supply home remedies. A livestock case does not establish a dog or cat dose. A horticultural “deer-resistant” label does not establish pet safety.
## Source scope
- S26 supports human emergency contacts, emergency signs and the instruction not to induce vomiting.
- S04 supports the ASPCA contact and consultation-fee note.
- S22 concerns foxtail/grass-awn injuries broadly, not a single grass species.
- S25 supports the limitation that even non-toxic plants can cause gastrointestinal upset.
- S27 supports the distinction between noxious-weed designation and general garden weeds; labels and local programs must be rechecked before action.
- Fremont-list-definitions supports the A/B/C management definitions and the distinction between state recommendations and local requirements for List C. The short action labels are editorial paraphrases; preserve the location-dependent requirements for List B and List C.
The hazard vocabulary and information-gathering checklist are editorial organization, not quoted clinical protocols.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/safety/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/safety/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/safety/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json
# FILE: https://denson.github.io/colorado-weed-field-guide/sources/index.md
---
{}
---
# Sources and photo credits
Every profile links its claims to these references. Retrieval dates record when a source was accessed; they are not publication dates. Photo credits appear beside each image and in the full ledger.
## A-loco
[Locoweed (Astragalus and Oxytropis spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/locoweed-astragalus-and-oxytropis-spp/) — USDA Agricultural Research Service.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:18+00:00. Source publication/update: not established.
## C-banner
[Rural Living Guide: Agriculture and Livestock](https://boulder.extension.colostate.edu/wp-content/uploads/sites/7/2021/03/BoCo-Rural-Living-Guide-Agriculture-Livestock-Rev-1.pdf) — CSU Extension, Boulder County.
Locator: Other Common Plants that may be Poisonous to Livestock: Golden Banner (Thermopsis divaricarpa). Accessed: 2026-09-07T00:31:28+00:00. Source publication/update: not established.
## C-descriptions
[Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/) — Colorado State University Extension.
Locator: Species entries. Accessed: 2026-09-07T00:24:02+00:00. Source publication/update: not established.
## C-foxtail
[Foxtail barley](https://extension.colostate.edu/resource/foxtail-barley/) — Colorado State University Extension.
Locator: Species entries. Accessed: 2026-09-07T00:24:02+00:00. Source publication/update: Published 2014-12; reviewed 2025-08.
## C-perennials
[Native Herbaceous Perennials for Colorado Landscapes](https://extension.colostate.edu/resource/native-herbaceous-perennials-for-colorado-landscapes/) — Colorado State University Extension.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:17+00:00. Source publication/update: not established.
## F-fringed
[Artemisia frigida species review](https://research.fs.usda.gov/feis/species-reviews/artfri) — US Forest Service.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:21+00:00. Source publication/update: not established.
## F-locoweed
[Oxytropis sericea species review](https://research.fs.usda.gov/feis/species-reviews/oxyser) — US Forest Service.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:18+00:00. Source publication/update: 1993-02.
## I-buffalobur
[Buffalobur](https://crops.extension.iastate.edu/encyclopedia/buffalobur) — Iowa State University Extension.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:17+00:00. Source publication/update: not established.
## J-bull-thistle
[Bull Thistle](https://www.jeffco.us/2618/Bull-Thistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:21+00:00. Source publication/update: 2025-10-14.
## J-canada-thistle
[Canada Thistle](https://www.jeffco.us/2616/Canada-Thistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:21+00:00. Source publication/update: 2025-09-22.
## J-dalmatian-toadflax
[Dalmatian Toadflax](https://www.jeffco.us/2469/Dalmatian-Toadflax) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:22+00:00. Source publication/update: not established.
## J-dames-rocket
[Dames Rocket](https://www.jeffco.us/2467/Dames-Rocket) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:22+00:00. Source publication/update: 2025-09-23.
## J-houndstongue
[Houndstongue](https://www.jeffco.us/2414/Houndstongue) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:22+00:00. Source publication/update: not established.
## J-leafy-spurge
[Leafy Spurge](https://www.jeffco.us/2406/Leafy-Spurge) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:23+00:00. Source publication/update: not established.
## J-musk-thistle
[Musk Thistle](https://www.jeffco.us/2384/Musk-Thistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:23+00:00. Source publication/update: 2025-09-22.
## J-oxeye-daisy
[Oxeye Daisy](https://www.jeffco.us/2340/Oxeye-Daisy) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:24+00:00. Source publication/update: 2025-10-14.
## J-russian-knapweed
[Russian knapweed](https://www.jeffco.us/4107/Russian-knapweed) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:24+00:00. Source publication/update: 2025-10-14.
## J-russian-olive
[Russian Olive](https://www.jeffco.us/2224/Russian-Olive) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:25+00:00. Source publication/update: 2025-09-22.
## J-saltcedar---tamarisk
[Saltcedar - Tamarisk](https://www.jeffco.us/2216/Saltcedar---Tamarisk) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:25+00:00. Source publication/update: 2025-10-14.
## J-scotch-thistle
[Scotch Thistle](https://www.jeffco.us/2192/Scotch-Thistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:26+00:00. Source publication/update: 2025-09-25.
## J-spotted-knapweed
[Spotted Knapweed](https://www.jeffco.us/2181/Spotted-Knapweed) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:26+00:00. Source publication/update: 2025-10-07.
## J-teasel
[Teasel](https://www.jeffco.us/2152/Teasel) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:26+00:00. Source publication/update: 2025-10-14.
## J-yellow-toadflax
[Yellow Toadflax](https://www.jeffco.us/2142/Yellow-Toadflax) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:27+00:00. Source publication/update: 2025-11-26.
## K-bindweed
[Bindweeds: field and hedge bindweed](https://blogs.cornell.edu/weedid/859-2/) — Cornell University.
Locator: Field bindweed description, alkaloids and livestock, management. Accessed: 2026-09-07T00:31:29+00:00. Source publication/update: not established.
## N-achillea-filipendulina
[Achillea filipendulina — Plant Toolbox](https://plants.ces.ncsu.edu/plants/achillea-filipendulina/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:59+00:00. Source publication/update: not established.
## N-ambrosia-artemisiifolia
[Ambrosia artemisiifolia — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## N-artemisia-ludoviciana
[Artemisia ludoviciana — Plant Toolbox](https://plants.ces.ncsu.edu/plants/artemisia-ludoviciana/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:57+00:00. Source publication/update: not established.
## N-centranthus-ruber
[Centranthus ruber — Plant Toolbox](https://plants.ces.ncsu.edu/plants/centranthus-ruber/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:59+00:00. Source publication/update: not established.
## N-convolvulus-arvensis
[Convolvulus arvensis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/convolvulus-arvensis/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:24:00+00:00. Source publication/update: not established.
## N-euphorbia-esula
[Euphorbia esula — Plant Toolbox](https://plants.ces.ncsu.edu/plants/euphorbia-esula/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:24:01+00:00. Source publication/update: not established.
## N-gaillardia-aristata
[Gaillardia aristata — Plant Toolbox](https://plants.ces.ncsu.edu/plants/gaillardia-aristata/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:59+00:00. Source publication/update: not established.
## N-leucanthemum-vulgare
[Leucanthemum vulgare — Plant Toolbox](https://plants.ces.ncsu.edu/plants/leucanthemum-vulgare/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:24:01+00:00. Source publication/update: not established.
## N-linum-lewisii
[Linum lewisii — Plant Toolbox](https://plants.ces.ncsu.edu/plants/linum-lewisii/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:59+00:00. Source publication/update: not established.
## N-nepeta-x-faassenii
[Nepeta x faassenii — Plant Toolbox](https://plants.ces.ncsu.edu/plants/nepeta-x-faassenii/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:58+00:00. Source publication/update: not established.
## N-rhaponticum-repens
[Rhaponticum repens — Plant Toolbox](https://plants.ces.ncsu.edu/plants/rhaponticum-repens/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:24:01+00:00. Source publication/update: not established.
## N-solidago-canadensis
[Solidago canadensis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/solidago-canadensis/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:58+00:00. Source publication/update: not established.
## N-stachys-byzantina
[Stachys byzantina — Plant Toolbox](https://plants.ces.ncsu.edu/plants/stachys-byzantina/) — NC State Extension.
Locator: Description, Attributes, Poisonous to Humans, Problems. Accessed: 2026-09-07T00:23:58+00:00. Source publication/update: not established.
## S01
[Native Plants](https://extension.colostate.edu/resource/native-plants/) — Colorado State University Extension.
Locator: Ecoregions and identifying plants. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S02
[Low Water Native Plants for Pollinators](https://pueblo.extension.colostate.edu/low-water-native-plants-for-pollinators/) — CSU Extension · Pueblo County.
Locator: Mid-Season Wildflowers: Showy Milkweed. Accessed: 2026-09-07T00:23:52+00:00. Source publication/update: not established.
## S03
[Low-Water Native Plants for Colorado Gardens: Front Range & Foothills](https://www.extension.colostate.edu/docs/pubs/native/FrontRangeSm.pdf) — Colorado Native Plant Society / CSU Extension.
Locator: Plant table: Asclepias speciosa and Achillea millefolium. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S04
[Milkweed](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/milkweed) — ASPCA Poison Control.
Locator: Scientific Name; Toxicity; Clinical Signs; poison contact. Accessed: 2026-09-07T00:23:52+00:00. Source publication/update: not established.
## S05
[Milkweed plants can cause serious poisoning](https://www.poison.org/articles/milkweed-can-cause-serious-poisoning-204) — National Capital Poison Center.
Locator: Symptoms; Effects on skin and in eyes; prevention. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S06
[Managing Western Whorled Milkweed](https://extension.colostate.edu/resource/managing-western-whorled-milkweed/) — Colorado State University Extension.
Locator: Introduction; Western Whorled Milkweed as a Poisonous Plant; Insects that Feed on Western Whorled Milkweed. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: Reviewed August 2025; published February 2014.
## S07
[Achillea millefolium](https://plants.ces.ncsu.edu/plants/achillea-millefolium/) — NC State Extension · Plant Toolbox.
Locator: Description; Problems; Wildlife Value. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S08
[Yarrow](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yarrow) — ASPCA Poison Control.
Locator: Scientific Name; Toxicity; Clinical Signs. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S09
[Yucca glauca](https://plants.ces.ncsu.edu/plants/yucca-glauca/) — NC State Extension · Plant Toolbox.
Locator: Description; needle-sharp leaf points; wildlife relationships. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S10
[Yucca](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/yucca) — ASPCA Poison Control.
Locator: Scientific Name; Toxicity; Clinical Signs. Accessed: 2026-09-07T00:23:53+00:00. Source publication/update: not established.
## S11
[Ground Cover Plants](https://extension.colostate.edu/resource/ground-cover-plants/) — Colorado State University Extension.
Locator: Table 1b: hot, dry, sunny exposures; Cerastium tomentosum. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: not established.
## S12
[Cerastium tomentosum](https://plants.ces.ncsu.edu/plants/cerastium-tomentosum/) — NC State Extension · Plant Toolbox.
Locator: Description; origin; Wildlife Value. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: not established.
## S13
[Myrtle spurge](https://ag.colorado.gov/conservation/noxious-weeds/colorado-noxious-weed-list/myrtle-spurge) — Colorado Department of Agriculture.
Locator: Species description. Accessed: 2026-09-06. Source publication/update: not established.
## S14
[Myrtle Spurge](https://www.jeffco.us/2364/Myrtle-Spurge) — Jefferson County, Colorado.
Locator: List A designation; General; Plant. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: 2025-09-22.
## S15
[Euphorbia myrsinites](https://plants.ces.ncsu.edu/plants/euphorbia-myrsinites/) — NC State Extension · Plant Toolbox.
Locator: Description; Poisonous to Humans; Problems. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: not established.
## S16
[Poison Hemlock](https://www.jeffco.us/2230/Poison-Hemlock) — Jefferson County, Colorado.
Locator: List C designation; General; Habitat; Vegetation; Flower. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: 2025-09-17.
## S17
[2109 – Puncture Vine](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2109-puncture-vine/) — PlantTalk Colorado · CSU Extension.
Locator: What is a puncture vine?; How can I control puncture vines?. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## S18
[Puncturevine / Home and Landscape](https://ipm.ucanr.edu/home-and-landscape/puncturevine/) — University of California Statewide IPM.
Locator: Pest Notes introduction; Identification and Life Cycle; Impact; Management. Accessed: 2026-09-07T00:23:55+00:00. Source publication/update: March 2006.
## S19
[Here They Come!](https://pueblo.extension.colostate.edu/here-they-come/) — CSU Extension · Pueblo County.
Locator: Puncturevine seed-casings and animal injury; herbicide label guidance. Accessed: 2026-09-07T00:23:54+00:00. Source publication/update: 2020.
## S20
[Cheatgrass and Wildfire](https://extension.colostate.edu/resource/cheatgrass-and-wildfire/) — Colorado State University Extension.
Locator: Introduction; How to Identify Cheatgrass; Fire Hazards. Accessed: 2026-09-07T00:23:55+00:00. Source publication/update: not established.
## S21
[Source Unit in Range and Pasture Management](https://cmg.extension.colostate.edu/wp-content/uploads/sites/42/2016/10/SourceUnitInRangeAndPastureMngmt_REVISED_5-22-2017.pdf) — Colorado State University Extension.
Locator: Printed page 44: plants that can cause mechanical injury. Accessed: 2026-09-07T00:23:55+00:00. Source publication/update: Revision May 22, 2017.
## S22
[Foxtails and Dogs](https://healthtopics.vetmed.ucdavis.edu/health-topics/foxtails) — UC Davis · School of Veterinary Medicine.
Locator: Takeaways; signs; prevention. Accessed: 2026-09-06. Source publication/update: May 8, 2023.
## S23
[Helianthus annuus](https://plants.ces.ncsu.edu/plants/helianthus-annuus/) — NC State Extension · Plant Toolbox.
Locator: Description; distribution; self-seeding; Wildlife Value. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## S24
[Plants to Support Your Local Wildlife](https://www.aspca.org/news/plants-support-your-local-wildlife) — ASPCA Poison Control.
Locator: Plants that are non-toxic to dogs and cats: common sunflower (Helianthus annuus). Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: May 14, 2026.
## S25
[Toxic and Non-Toxic Plants](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants) — ASPCA Poison Control.
Locator: Any plant material may cause vomiting or gastrointestinal upset; database limitations. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## S26
[First aid guidelines](https://www.poison.org/first-aid-for-poisonings) — National Capital Poison Center.
Locator: Poison center phone; emergency symptoms; do not induce vomiting. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## S27
[2103 – Colorado Noxious Weeds](https://planttalk.colostate.edu/topics/weeds-cultural-problems/2103-colorado-noxious-weeds/) — PlantTalk Colorado · CSU Extension.
Locator: List A, B and C management categories. Accessed: 2026-09-07T00:23:57+00:00. Source publication/update: not established.
## S28
[Loving Our Native Plants](https://pueblo.extension.colostate.edu/loving-our-native-plants/) — CSU Extension · Pueblo County.
Locator: Native landscape plant list: Common sunflower and Showy milkweed. Accessed: 2026-09-07T00:23:56+00:00. Source publication/update: not established.
## S29
[Weed Management Reference Guide](https://www.larimer.gov/sites/default/files/uploads/2023/weed_management_reference_guide_-_5.5_x_8_-_jan_24_2023_-_website_reader_spreads_0.pdf) — Larimer County, Colorado.
Locator: Puncturevine entry: List C. Accessed: 2026-09-07T00:24:00+00:00. Source publication/update: January 24, 2023.
## ST-pattern
[The Stoagen pattern](https://stoagen.com/pattern/index.md) — Stoagen.
Locator: Published Markdown mirror and agent appendix pattern. Accessed: 2026-09-07T00:31:30+00:00. Source publication/update: not established.
## U-buffalobur
[Solanum rostratum herbarium collection records](https://botany-server3.colorado.edu/collections/list.php?page=3&taxa=2365&taxontype=2&usethes=1) — University of Colorado Museum of Natural History.
Locator: COLO:V specimens 00785139 and 00785204; Colorado localities. Accessed: 2026-09-07. Source publication/update: not established.
## W-buffalobur
[Buffalobur](https://www.nwcb.wa.gov/weeds/buffalobur) — Washington State Noxious Weed Control Board.
Locator: Description, distribution, hazards, management; see claim locator. Accessed: 2026-09-07T00:27:17+00:00. Source publication/update: not established.
## N-russian-sage
[Russian sage (Salvia yangii)](https://plants.ces.ncsu.edu/plants/salvia-yangii/) — NC State Extension.
Locator: Description, synonyms, native range, wildlife value. Accessed: 2026-09-07T00:57:24+00:00. Source publication/update: not established.
## C-russian-sage
[1050: Russian Sage](https://planttalk.colostate.edu/topics/annuals-perennials/1050-russian-sage/) — Colorado State University Extension / PlantTalk.
Locator: Colorado garden use; taxonomy sentence is outdated relative to NC State. Accessed: 2026-09-07T00:57:25+00:00. Source publication/update: not established.
## E-sage-suckers
[Russian Sage Suckers](https://ask.extension.org/kb/faq.php?id=639127) — Ask Extension.
Locator: Expert response on sucker growth. Accessed: 2026-09-07T00:57:24+00:00. Source publication/update: not established.
## C-tumbleweeds
[Identification and Management of Kochia and Russian Thistle](https://extension.colostate.edu/resource/identification-and-management-of-kochia-and-russian-thistle/) — Colorado State University Extension.
Locator: Weed Description; Livestock Poisonings; Integrated Weed Management. Accessed: 2026-09-07T00:57:25+00:00. Source publication/update: not established.
## CO-rules-2025
[Colorado Noxious Weed Act rules, 8 CCR 1206-2](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2) — Colorado Secretary of State / Department of Agriculture.
Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025. Accessed: 2026-09-07T01:07:48+00:00. Source publication/update: 2025-05-15.
## UC-russian-thistle
[Russian Thistle](https://ipm.ucanr.edu/weeds-identification-gallery/russian-thistle/) — University of California Statewide IPM.
Locator: Taxonomic complex, morphology, oxalates, dry tumbleweed hazards. Accessed: 2026-09-07T00:57:25+00:00. Source publication/update: not established.
## N-euphorbia-cyparissias
[euphorbia cyparissias — Plant Toolbox](https://plants.ces.ncsu.edu/plants/euphorbia-cyparissias/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:51+00:00. Source publication/update: not established.
## N-isatis-tinctoria
[isatis tinctoria — Plant Toolbox](https://plants.ces.ncsu.edu/plants/isatis-tinctoria/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:51+00:00. Source publication/update: not established.
## N-arundo-donax
[arundo donax — Plant Toolbox](https://plants.ces.ncsu.edu/plants/arundo-donax/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:51+00:00. Source publication/update: not established.
## N-salvinia-molesta
[salvinia molesta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/salvinia-molesta/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:51+00:00. Source publication/update: not established.
## N-epilobium-hirsutum
[epilobium hirsutum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/epilobium-hirsutum/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:51+00:00. Source publication/update: not established.
## N-hydrilla-verticillata
[hydrilla verticillata — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hydrilla-verticillata/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:52+00:00. Source publication/update: not established.
## N-reynoutria-japonica
[reynoutria japonica — Plant Toolbox](https://plants.ces.ncsu.edu/plants/reynoutria-japonica/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:52+00:00. Source publication/update: not established.
## N-myriophyllum-aquaticum
[myriophyllum aquaticum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/myriophyllum-aquaticum/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:52+00:00. Source publication/update: not established.
## N-lythrum-salicaria
[lythrum salicaria — Plant Toolbox](https://plants.ces.ncsu.edu/plants/lythrum-salicaria/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:52+00:00. Source publication/update: not established.
## N-iris-pseudacorus
[iris pseudacorus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/iris-pseudacorus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-centaurea-solstitialis
[centaurea solstitialis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/centaurea-solstitialis/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-artemisia-absinthium
[artemisia absinthium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/artemisia-absinthium/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-hyoscyamus-niger
[hyoscyamus niger — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hyoscyamus-niger/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-saponaria-officinalis
[saponaria officinalis — Plant Toolbox](https://plants.ces.ncsu.edu/plants/saponaria-officinalis/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-tanacetum-vulgare
[tanacetum vulgare — Plant Toolbox](https://plants.ces.ncsu.edu/plants/tanacetum-vulgare/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:53+00:00. Source publication/update: not established.
## N-myriophyllum-spicatum
[myriophyllum spicatum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/myriophyllum-spicatum/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:54+00:00. Source publication/update: not established.
## N-potentilla-recta
[potentilla recta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/potentilla-recta/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:54+00:00. Source publication/update: not established.
## N-carum-carvi
[carum carvi — Plant Toolbox](https://plants.ces.ncsu.edu/plants/carum-carvi/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:54+00:00. Source publication/update: not established.
## N-cyperus-esculentus
[cyperus esculentus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/cyperus-esculentus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:54+00:00. Source publication/update: not established.
## N-cichorium-intybus
[cichorium intybus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/cichorium-intybus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-arctium-minus
[arctium minus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/arctium-minus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-verbascum-thapsus
[verbascum thapsus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/verbascum-thapsus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-hypericum-perforatum
[hypericum perforatum — Plant Toolbox](https://plants.ces.ncsu.edu/plants/hypericum-perforatum/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-sorghum-halepense
[sorghum halepense — Plant Toolbox](https://plants.ces.ncsu.edu/plants/sorghum-halepense/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-ulmus-pumila
[ulmus pumila — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ulmus-pumila/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## N-ailanthus-altissima
[ailanthus altissima — Plant Toolbox](https://plants.ces.ncsu.edu/plants/ailanthus-altissima/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:55+00:00. Source publication/update: not established.
## WA-common-crupina
[Common Crupina](https://www.nwcb.wa.gov/weeds/common-crupina) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:08:59+00:00. Source publication/update: not established.
## WA-camelthorn
[Camelthorn](https://www.nwcb.wa.gov/weeds/camelthorn) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:08:59+00:00. Source publication/update: not established.
## WA-flowering-rush
[Flowering Rush](https://www.nwcb.wa.gov/weeds/flowering-rush) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:08:59+00:00. Source publication/update: not established.
## WA-giant-knotweed
[Giant Knotweed](https://www.nwcb.wa.gov/weeds/giant-knotweed) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:00+00:00. Source publication/update: not established.
## WA-bohemian-knotweed
[Bohemian Knotweed](https://www.nwcb.wa.gov/weeds/bohemian-knotweed) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:00+00:00. Source publication/update: not established.
## WA-meadow-knapweed
[Meadow Knapweed](https://www.nwcb.wa.gov/weeds/meadow-knapweed) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:00+00:00. Source publication/update: not established.
## WA-mediterranean-sage
[Mediterranean Sage](https://www.nwcb.wa.gov/weeds/mediterranean-sage) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:00+00:00. Source publication/update: not established.
## WA-medusahead
[Medusahead](https://www.nwcb.wa.gov/weeds/medusahead) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:00+00:00. Source publication/update: not established.
## WA-orange-hawkweed
[Orange Hawkweed](https://www.nwcb.wa.gov/weeds/orange-hawkweed) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:01+00:00. Source publication/update: not established.
## WA-rush-skeletonweed
[Rush Skeletonweed](https://www.nwcb.wa.gov/weeds/rush-skeletonweed) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:01+00:00. Source publication/update: not established.
## WA-tansy-ragwort
[Tansy Ragwort](https://www.nwcb.wa.gov/weeds/tansy-ragwort) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:01+00:00. Source publication/update: not established.
## WA-ventenata
[Ventenata](https://www.nwcb.wa.gov/weeds/ventenata) — Washington State Noxious Weed Control Board.
Locator: Identification, ecological impacts, management; Washington legal class not applied to Colorado. Accessed: 2026-09-07T01:09:01+00:00. Source publication/update: not established.
## J-chinese-clematis
[Chinese Clematis](https://www.jeffco.us/2530/Chinese-Clematis) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:55+00:00. Source publication/update: not established.
## N-clematis
[Clematis](https://plants.ces.ncsu.edu/plants/clematis/) — NC State Extension.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:20+00:00. Source publication/update: not established.
## J-hoary-cress
[Hoary Cress](https://www.jeffco.us/2436/Hoary-Cress) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:56+00:00. Source publication/update: not established.
## J-jointed-goatgrass
[Jointed Goatgrass](https://www.jeffco.us/2413/Jointed-Goatgrass) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:57+00:00. Source publication/update: not established.
## J-moth-mullein
[Moth Mullein](https://www.jeffco.us/2402/Moth-Mullein) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:57+00:00. Source publication/update: not established.
## J-perennial-pepperweed
[Perennial Pepperweed](https://www.jeffco.us/2334/Perennial-Pepperweed) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:57+00:00. Source publication/update: not established.
## J-plumeless-thistle
[Plumeless Thistle](https://www.jeffco.us/2294/Plumeless-Thistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:24+00:00. Source publication/update: not established.
## J-perennial-sowthistle
[Perennial Sowthistle](https://www.jeffco.us/2323/Perennial-Sowthistle) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:24+00:00. Source publication/update: not established.
## J-redstem-filaree
[Redstem Filaree](https://www.jeffco.us/2240/Redstem-Filaree) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:58+00:00. Source publication/update: not established.
## J-scentless-chamomile
[Scentless Chamomile](https://www.jeffco.us/2205/Scentless-Chamomile) — Jefferson County, Colorado.
Locator: Species description and management. Accessed: 2026-09-07T01:08:59+00:00. Source publication/update: not established.
## J-diffuse-knapweed
[Diffuse Knapweed](https://www.jeffco.us/2466/Diffuse-Knapweed) — Jefferson County, Colorado.
Locator: Description, impacts, Colorado list designation, management. Accessed: 2026-09-07T00:27:22+00:00. Source publication/update: not established.
## NPS-african
[African Rue](https://www.nps.gov/whsa/learn/nature/africanrue.htm) — US National Park Service.
Locator: Species identity, description, ecology and exposure evidence. Accessed: 2026-09-07T01:21:13+00:00. Source publication/update: not established.
## WA-african-rue
[African rue](https://www.nwcb.wa.gov/weeds/african-rue) — Washington State Noxious Weed Control Board.
Locator: Species or hybrid identity, description and ecology. Accessed: 2026-09-07T01:18:56+00:00. Source publication/update: not established.
## CO-elongated-mustard
[Elongated mustard identification and management](https://fremontcountyco.gov/sites/default/files/weed-control/weed-files/elongated-mustard-fact-sheet.pdf) — Colorado Department of Agriculture, hosted by Fremont County.
Locator: Identification and impacts; updated July 2015. Accessed: 2026-09-07T01:14:00+00:00. Source publication/update: not established.
## NPS-squarrose
[Exotic Species: Squarrose Knapweed](https://www.nps.gov/articles/squarrose-knapweed.htm) — US National Park Service.
Locator: Species or hybrid identity, description and ecology. Accessed: 2026-09-07T01:18:57+00:00. Source publication/update: not established.
## F-teasels
[Fuller’s and cutleaf teasel](https://research.fs.usda.gov/feis/species-reviews/dipspp) — USDA Forest Service.
Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted. Accessed: 2026-09-07T01:34:00+00:00. Source publication/update: not established.
## F-toadflaxes
[Biology and Biological Control of Dalmatian and Yellow Toadflax](https://www.govinfo.gov/content/pkg/GOVPUB-A13-PURL-gpo87594/pdf/GOVPUB-A13-PURL-gpo87594.pdf) — USDA Forest Service.
Locator: Species or hybrid identity, description and ecology. Accessed: 2026-09-07T01:19:10+00:00. Source publication/update: not established.
## UC-mayweed
[Mayweed chamomile](https://ipm.ucanr.edu/weeds-identification-gallery/mayweed-chamomile/) — University of California Statewide IPM.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## K-chamomiles
[Chamomiles](https://cals.cornell.edu/weed-science/weed-profiles/chamomiles) — Cornell University College of Agriculture and Life Sciences.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## P-tauricum
[Morphological and Genomic Differences in the Italian Populations of Onopordum tauricum](https://pmc.ncbi.nlm.nih.gov/articles/PMC10934427/) — Plants journal / authors; archived by US National Library of Medicine.
Locator: Species or hybrid identity, description and ecology. Accessed: 2026-09-07T01:18:57+00:00. Source publication/update: not established.
## F-knapweed
[Diffuse knapweed and hybrid taxonomy](https://research.fs.usda.gov/feis/species-reviews/cendif) — USDA Forest Service Fire Effects Information System.
Locator: Species identity, description, ecology and exposure evidence. Accessed: 2026-09-07T01:21:11+00:00. Source publication/update: not established.
## U-bulbous
[Bulbous bluegrass](https://extension.usu.edu/rangeplants/grasses-and-grasslikes/bulbous-bluegrass) — Utah State University Extension.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:17+00:00. Source publication/update: not established.
## A-halogeton
[Halogeton (Halogeton glomeratus)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/halogeton-halogeton-glomeratus/) — USDA Agricultural Research Service.
Locator: Description; distribution; poisoning; management. Accessed: 2026-09-07T01:13:59+00:00. Source publication/update: not established.
## M-quackgrass
[Quackgrass](https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/quackgrass) — University of Minnesota Extension.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:17+00:00. Source publication/update: not established.
## K-velvetleaf
[Velvetleaf](https://cals.cornell.edu/weed-science/weed-profiles/velvetleaf) — Cornell University College of Agriculture and Life Sciences.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## K-wild-proso
[Wild-proso millet](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet) — Cornell University College of Agriculture and Life Sciences.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## N-datura-stramonium
[datura stramonium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/datura-stramonium/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## C-routt-guide
[Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf) — Routt County / Colorado State University Extension.
Locator: Common weeds and poisonous plants; 2021 edition. Accessed: 2026-09-07T01:14:14+00:00. Source publication/update: not established.
## N-xanthium-strumarium
[xanthium strumarium — Plant Toolbox](https://plants.ces.ncsu.edu/plants/xanthium-strumarium/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## C-wetland-guide
[Common Wetland Plants of Colorado’s Western Slope](https://cnhp.colostate.edu/wp-content/uploads/download/documents/cwic_docs/WesternSlope.pdf) — Colorado Natural Heritage Program / Colorado State University.
Locator: Water hemlock and western poison ivy entries; taxonomic scope. Accessed: 2026-09-07T01:14:13+00:00. Source publication/update: not established.
## U-water-hemlock
[Water Hemlock](https://extension.usu.edu/rangeplants/forbs-herbaceous/water-hemlock) — Utah State University Extension.
Locator: Cicuta douglasii identification and toxicity. Accessed: 2026-09-07T01:14:00+00:00. Source publication/update: not established.
## FDA-poison-ivy
[Outsmarting Poison Ivy and Other Poisonous Plants](https://www.fda.gov/consumers/consumer-updates/outsmarting-poison-ivy-and-other-poisonous-plants) — US Food and Drug Administration.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## N-amaranthus-retroflexus
[amaranthus retroflexus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/amaranthus-retroflexus/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## N-portulaca-oleracea
[portulaca oleracea — Plant Toolbox](https://plants.ces.ncsu.edu/plants/portulaca-oleracea/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## A-purslane
[Purslane](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/purslane) — ASPCA Poison Control.
Locator: Scientific name, toxicity to dogs, cats and horses. Accessed: 2026-09-07T01:14:01+00:00. Source publication/update: not established.
## N-taraxacum-officinale
[taraxacum officinale — Plant Toolbox](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## N-solanum-dulcamara
[solanum dulcamara — Plant Toolbox](https://plants.ces.ncsu.edu/plants/solanum-dulcamara/) — NC State Extension.
Locator: Description; Attributes; Problems; Poisonous to Humans. Accessed: 2026-09-07T01:04:56+00:00. Source publication/update: not established.
## ARS-larkspur
[Larkspur (Delphinium spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/) — USDA Agricultural Research Service.
Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted. Accessed: 2026-09-07T01:34:00+00:00. Source publication/update: not established.
## A-larkspur
[Larkspur — Delphinium species](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur) — ASPCA Poison Control.
Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted. Accessed: 2026-09-07T01:34:00+00:00. Source publication/update: not established.
## B-deathcamas
[Toxicoscordion venenosum var. gramineum](https://burkeherbarium.org/imagecollection/taxon.php?Taxon=Toxicoscordion+venenosum+var.+gramineum) — University of Washington Burke Herbarium; Don Knoke and David Giblin.
Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted. Accessed: 2026-09-07T01:34:00+00:00. Source publication/update: not established.
## ARS-deathcamas
[Deathcamas](https://www.ars.usda.gov/Services/docs.htm?docid=9861) — USDA Agricultural Research Service.
Locator: Description; toxicity; species group including Zigadenus venenosus. Accessed: 2026-09-07T01:37:13+00:00. Source publication/update: not established.
## N-chenopodium-album
[chenopodium album — Plant Toolbox](https://plants.ces.ncsu.edu/plants/chenopodium-album/) — NC State Extension.
Locator: Species identity, description, ecology, toxicity. Accessed: 2026-09-07T01:21:10+00:00. Source publication/update: not established.
## C-edible-weeds
[Early Spring Edible Plants In Your Yard And Garden](https://pueblo.extension.colostate.edu/early-spring-edible-plants-in-your-yard-and-garden/) — Colorado State University Extension, Pueblo County.
Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted. Accessed: 2026-09-07T01:34:00+00:00. Source publication/update: not established.
## N-rumex-crispus
[rumex crispus — Plant Toolbox](https://plants.ces.ncsu.edu/plants/rumex-crispus/) — NC State Extension.
Locator: Species identity, description, ecology, toxicity. Accessed: 2026-09-07T01:21:11+00:00. Source publication/update: not established.
## N-malva-neglecta
[malva neglecta — Plant Toolbox](https://plants.ces.ncsu.edu/plants/malva-neglecta/) — NC State Extension.
Locator: Species identity, description, ecology, toxicity. Accessed: 2026-09-07T01:21:11+00:00. Source publication/update: not established.
## A-caraway
[Caraway](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/caraway) — ASPCA Poison Control.
Locator: Scientific name and toxicity. Accessed: 2026-09-07T01:14:01+00:00. Source publication/update: not established.
## A-ragwort
[Ragwort](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/ragwort) — ASPCA Poison Control.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:20+00:00. Source publication/update: not established.
## K-kochia
[Kochia](https://cals.cornell.edu/weed-science/weed-profiles/kochia) — Cornell University College of Agriculture and Life Sciences.
Locator: Species identity, description, ecological and exposure evidence; verify group scope. Accessed: 2026-09-07T01:16:19+00:00. Source publication/update: not established.
## C-floristic-2020
[Revision of Colorado’s Floristic Quality Assessment Indices, 2020](https://cnhp.colostate.edu/download/documents/2020/CO_FQA_2020_Final_Report.pdf) — Colorado Natural Heritage Program, Colorado State University.
Locator: Appendix B, Colorado species list: scientific name and native/non-native fields. Accessed: 2026-09-07T02:27:33+00:00. Source publication/update: 2020-12.
## N-digitaria-sanguinalis
[Digitaria sanguinalis](https://plants.ces.ncsu.edu/plants/digitaria-sanguinalis/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-setaria-viridis
[Setaria viridis](https://plants.ces.ncsu.edu/plants/setaria-viridis/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-polygonum-aviculare
[Polygonum aviculare](https://plants.ces.ncsu.edu/plants/polygonum-aviculare/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-euphorbia-maculata
[Euphorbia maculata](https://plants.ces.ncsu.edu/plants/euphorbia-maculata/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-capsella-bursa-pastoris
[Capsella bursa pastoris](https://plants.ces.ncsu.edu/plants/capsella-bursa-pastoris/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-melilotus-officinalis
[Melilotus officinalis](https://plants.ces.ncsu.edu/plants/melilotus-officinalis/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## F-melilotus
[White and yellow sweetclover](https://research.fs.usda.gov/feis/species-reviews/melspp) — USDA Forest Service, Fire Effects Information System.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:14+00:00. Source publication/update: not established.
## N-oxalis-corniculata
[Oxalis corniculata](https://plants.ces.ncsu.edu/plants/oxalis-corniculata/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-trifolium-repens
[Trifolium repens](https://plants.ces.ncsu.edu/plants/trifolium-repens/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-viola-sororia
[Viola sororia](https://plants.ces.ncsu.edu/plants/viola-sororia/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:11+00:00. Source publication/update: not established.
## N-stellaria-media
[Stellaria media](https://plants.ces.ncsu.edu/plants/stellaria-media/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-lamium-amplexicaule
[Lamium amplexicaule](https://plants.ces.ncsu.edu/plants/lamium-amplexicaule/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-erigeron-canadensis
[Erigeron canadensis](https://plants.ces.ncsu.edu/plants/erigeron-canadensis/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## I-giant-ragweed
[Giant ragweed](https://crops.extension.iastate.edu/encyclopedia/giant-ragweed) — Iowa State University Extension.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:09+00:00. Source publication/update: not established.
## C-ragweed-native
[Ragweed](https://sam.extension.colostate.edu/wp-content/uploads/sites/44/2019/08/August-31-2019-Ragweed.pdf) — Colorado State University Extension.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:09+00:00. Source publication/update: not established.
## U-sowthistle
[Annual sowthistle](https://ipm.ucanr.edu/weeds-identification-gallery/annual-sowthistle/) — University of California Statewide Integrated Pest Management.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:10+00:00. Source publication/update: not established.
## N-sonchus-asper
[Sonchus asper](https://plants.ces.ncsu.edu/plants/sonchus-asper/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-galium-aparine
[Galium aparine](https://plants.ces.ncsu.edu/plants/galium-aparine/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-pastinaca-sativa
[Pastinaca sativa](https://plants.ces.ncsu.edu/plants/pastinaca-sativa/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## N-apocynum-cannabinum
[Apocynum cannabinum](https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:12+00:00. Source publication/update: not established.
## P-dogbane
[Dogbane hemp](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/dogbane-hemp) — ASPCA Animal Poison Control.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:10+00:00. Source publication/update: not established.
## F-apocynum
[Hemp dogbane](https://research.fs.usda.gov/feis/species-reviews/apocan) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:50+00:00. Source publication/update: not established.
## N-urtica-dioica
[Urtica dioica](https://plants.ces.ncsu.edu/plants/urtica-dioica/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:13+00:00. Source publication/update: not established.
## F-urtica
[Stinging nettle](https://research.fs.usda.gov/feis/species-reviews/urtdio) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:50+00:00. Source publication/update: not established.
## N-daucus-carota
[Daucus carota](https://plants.ces.ncsu.edu/plants/daucus-carota/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:13+00:00. Source publication/update: not established.
## F-gutierrezia
[Broom snakeweed](https://research.fs.usda.gov/feis/species-reviews/gutsar) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:48+00:00. Source publication/update: not established.
## F-grindelia
[Curlycup gumweed](https://research.fs.usda.gov/feis/species-reviews/grisqu) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:48+00:00. Source publication/update: not established.
## A-greasewood
[Greasewood (Sarcobatus vermiculatus)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/) — USDA Agricultural Research Service.
Locator: Identification, distribution and livestock poisoning; treatment instructions excluded. Accessed: 2026-09-07T02:24:50+00:00. Source publication/update: not established.
## F-sarcobatus
[Black greasewood](https://research.fs.usda.gov/feis/species-reviews/sarver) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:48+00:00. Source publication/update: not established.
## A-big-sagebrush
[Big sagebrush plant guide](https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_artrw8.pdf) — USDA Natural Resources Conservation Service.
Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions. Accessed: 2026-09-07T02:33:44+00:00. Source publication/update: not established.
## C-native-shrubs
[Native shrubs for Colorado landscapes](https://extension.colostate.edu/resource/native-shrubs-for-colorado-landscapes/) — Colorado State University Extension.
Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions. Accessed: 2026-09-07T02:33:44+00:00. Source publication/update: not established.
## F-opuntia
[Plains pricklypear](https://research.fs.usda.gov/feis/species-reviews/opupol) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:48+00:00. Source publication/update: not established.
## C-low-water-cactus
[Very Low Water Garden](https://elpaso.extension.colostate.edu/native-plant-demonstration-garden/very-low-water-garden/) — Colorado State University Extension, El Paso County.
Locator: Named species descriptions and landscape context; sagebrush subspecies distinctions. Accessed: 2026-09-07T02:33:43+00:00. Source publication/update: not established.
## F-ericameria
[Rubber rabbitbrush](https://research.fs.usda.gov/feis/species-reviews/erinau) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:48+00:00. Source publication/update: not established.
## F-ambrosia-psilostachya
[Western ragweed](https://research.fs.usda.gov/feis/species-reviews/ambpsi) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:49+00:00. Source publication/update: not established.
## N-euphorbia-marginata
[Euphorbia marginata](https://plants.ces.ncsu.edu/plants/euphorbia-marginata/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:13+00:00. Source publication/update: not established.
## U-silverleaf
[Silverleaf nightshade](https://ipm.ucanr.edu/weeds-identification-gallery/silverleaf-nightshade/) — University of California Statewide Integrated Pest Management.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:10+00:00. Source publication/update: not established.
## N-ranunculus-acris
[Ranunculus acris](https://plants.ces.ncsu.edu/plants/ranunculus-acris/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:13+00:00. Source publication/update: not established.
## P-buttercup
[Buttercup](https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/buttercup) — ASPCA Animal Poison Control.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:11+00:00. Source publication/update: not established.
## F-sisymbrium
[Tall tumblemustard](https://research.fs.usda.gov/feis/species-reviews/sisalt) — USDA Forest Service, Fire Effects Information System.
Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management. Accessed: 2026-09-07T02:24:49+00:00. Source publication/update: not established.
## N-securigera-varia
[Securigera varia](https://plants.ces.ncsu.edu/plants/securigera-varia/) — NC State Extension.
Locator: Description, identification attributes and plant problems; toxicity section where present. Accessed: 2026-09-07T02:23:14+00:00. Source publication/update: not established.
## F-securigera
[Crownvetch](https://research.fs.usda.gov/feis/species-reviews/secvar) — USDA Forest Service, Fire Effects Information System.
Locator: Named species or genus; identification, distribution and hazard sections where available. Accessed: 2026-09-07T02:26:13+00:00. Source publication/update: not established.
## Corteva-west
[Range & Pasture Western Rangeland Weed & Brush ID Guide](https://online.flippingbook.com/view/847083821/) — Corteva Agriscience.
Locator: 84 plant profile topics; per-row printed pages in coverage.json. Accessed: 2026-09-07T02:05:52+00:00. Source publication/update: not established.
## Fremont-list-definitions
[Weed Identification: Colorado List A, B and C definitions](https://fremontcountyco.gov/weed-control/weed-identification) — Fremont County, Colorado — Weed Management.
Locator: Opening paragraphs defining List A, List B and List C under the Colorado Noxious Weed Act. Accessed: 2026-09-07T03:48:41.948837+00:00. Source publication/update: not established.
# Appendix for agents
The ledger provides exact retrieval URLs and response hashes when downloads succeeded. A response hash establishes the bytes retrieved, not the truth of the source. Older sources and taxonomic ambiguities are identified in profile appendices.
---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/sources/
Content revised: 2026-09-21T19:48:00Z
Markdown mirror: https://denson.github.io/colorado-weed-field-guide/sources/index.md
Text fallback: https://denson.github.io/colorado-weed-field-guide/sources/index.md.txt
Agent entry: https://denson.github.io/colorado-weed-field-guide/start.md
Provenance: https://denson.github.io/colorado-weed-field-guide/provenance.json