--- { "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. ![Side view of yellow toadflax flowers and their long spurs beside developing reproductive structures, with a 10 mm scale.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-bc-photos-linaria-genistifolia-04.jpg) **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. ![Smooth, lance-shaped leaves along an upright toadflax stem, viewed against the sky.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-bc-photos-linaria-genistifolia-05.jpg) **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. ![Tall, slender, branching toadflax plant rising above surrounding grassland vegetation.](https://denson.github.io/colorado-weed-field-guide/assets/photos/list-bc-photos-linaria-genistifolia-08.jpg) **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