--- { "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. ![Small branching broom snakeweed plant with yellow flower clusters above a woody base on rocky ground.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-gutierrezia-sarothrae-habit-23477453.jpg) **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. ![Yellow broom snakeweed flower heads held against a hand, showing the small rays and central florets.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-gutierrezia-sarothrae-flowers-100211579.jpeg) **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. ![Slender green broom snakeweed stem and narrow leaves held against a hand.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-gutierrezia-sarothrae-leaves-stem-11379388.jpg) **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