---
{
  "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.

![Creeping woodsorrel: a low leafy patch of creeping woodsorrel with small yellow flowers.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-garden-photos-oxalis-corniculata-09-05-habit.jpg)

**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.

![Creeping woodsorrel: a yellow five-petaled flower with fine reddish veins near the center.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-garden-photos-oxalis-corniculata-09-08-flower.jpg)

**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.

![Creeping woodsorrel: an elongated pointed green capsule with fine surface hairs on a curved stalk, photographed with a 10 mm scale.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-garden-photos-oxalis-corniculata-09-36-fruit.jpg)

**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