--- { "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. ![Lamium amplexicaule: Several long purple tubular flowers rising from a whorl of rounded clasping leaves.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-hazard-photos-lamium-amplexicaule-1.jpg) **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. ![Lamium amplexicaule: Two open pink-purple tubular flowers with spotted lower lips above a leafy whorl.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-hazard-photos-lamium-amplexicaule-2.jpg) **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. ![Lamium amplexicaule: Rounded, scalloped upper leaves clasping stems around clusters of buds and small flowers.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-hazard-photos-lamium-amplexicaule-3.jpg) **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