---
{
  "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.

![Meadow buttercup growing among grass, with yellow flowers held above deeply divided basal leaves.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-ranunculus-acris-habit-flowers-102792093.jpeg)

**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.

![Deeply divided green basal leaves of meadow buttercup among surrounding grass.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-ranunculus-acris-leaves-102792144.jpeg)

**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.

![Cluster of green developing meadow buttercup achenes at the top of a slender stalk.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-ranunculus-acris-fruit-102792039.jpeg)

**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