---
{
  "id": "common-dandelion",
  "name": "Common dandelion",
  "scientific": "Taraxacum officinale",
  "category": "invasive",
  "status": "Common weed; not an A/B/C listing in the reviewed state rule",
  "status_sources": [
    "CO-rules-2025"
  ],
  "warning": "Persistent lawn volunteer; sap can irritate skin",
  "warning_tone": "caution",
  "aliases": [],
  "taxonomy_note": "Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.",
  "source_ids": [
    "CO-rules-2025",
    "N-taraxacum-officinale",
    "C-descriptions",
    "S27"
  ],
  "description": "Common dandelion: Persistent lawn volunteer; sap can irritate skin. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Recognize",
      "sources": [
        "N-taraxacum-officinale"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-dandelion-1"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "C-descriptions",
        "N-taraxacum-officinale"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-dandelion-2"
    },
    {
      "label": "People",
      "sources": [
        "N-taraxacum-officinale"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-dandelion-3"
    },
    {
      "label": "Dogs & cats",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "common-dandelion-4"
    },
    {
      "label": "Other animals",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "common-dandelion-5"
    }
  ],
  "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": [
          "common-dandelion-3"
        ]
      },
      {
        "area": "Dogs & cats",
        "question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
        "related_claim_ids": [
          "common-dandelion-4"
        ]
      },
      {
        "area": "Other animals",
        "question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
        "related_claim_ids": [
          "common-dandelion-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"
  },
  "source": "content/plants/common-dandelion.md"
}
---

# Common dandelion

*Taraxacum officinale*

**Common weed; not an A/B/C listing in the reviewed state rule.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)

> **Persistent lawn volunteer; sap can irritate skin.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.

## 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.

![Taraxacum officinale: Whole photographed plant with a taproot, basal lobed leaves, and a leafless stalk bearing a yellow flower head.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-taraxacum-officinale-21-13-habit.jpg)

**habit** — Whole photographed plant with a taproot, basal lobed leaves, and a leafless stalk bearing a yellow flower head.

Photo: FoeNyx; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Taraxacum-officinalis-plant.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/1/11/Taraxacum-officinalis-plant.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. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Taraxacum officinale: Rounded white seed head of many fruits, each attached to a radiating stalk and parachute-like pappus.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-taraxacum-officinale-21-15-seed-head.jpg)

**seed-head** — Rounded white seed head of many fruits, each attached to a radiating stalk and parachute-like pappus.

Photo: Michael Gäbler; [CC BY 3.0](https://creativecommons.org/licenses/by/3.0); [source record](https://commons.wikimedia.org/wiki/File:Ripe_fruits_by_Common_Dandelion.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/65/Ripe_fruits_by_Common_Dandelion.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. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Taraxacum officinale: Bright yellow flower heads made of many strap-shaped florets, with unopened buds and basal foliage nearby.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-taraxacum-officinale-21-16-flower.jpg)

**flower** — Bright yellow flower heads made of many strap-shaped florets, with unopened buds and basal foliage nearby.

Photo: Slick (German Wikipedia); [Public domain](https://commons.wikimedia.org/wiki/File:Taraxacum_officinale_flower_2005-05-01.jpg#Licensing); [source record](https://commons.wikimedia.org/wiki/File:Taraxacum_officinale_flower_2005-05-01.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/d/dc/Taraxacum_officinale_flower_2005-05-01.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. Common dandelion is represented as the T. officinale aggregate / section Ruderalia. Numerous microspecies cannot be resolved from these general photographs. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.


## Recognize

A basal rosette of toothed leaves, single yellow heads on hollow leafless stalks, and a rounded puffball of windborne seeds. [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)

## Plants & habitat

A familiar Colorado lawn plant with a persistent taproot. Flowers provide early pollen and nectar; removal is a site choice, not a claim that it has no ecological value. [C-descriptions](https://extension.colostate.edu/resource/weed-descriptions/) [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)

## People

Sap can cause contact dermatitis in susceptible people. Recorded food uses do not establish that an unidentified or treated lawn plant is safe to eat. [N-taraxacum-officinale](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/)

## 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.
- **N-taraxacum-officinale** — [taraxacum officinale — Plant Toolbox](https://plants.ces.ncsu.edu/plants/taraxacum-officinale/), NC State Extension. Accessed 2026-09-07T01:04:56+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- **C-descriptions** — [Weed descriptions](https://extension.colostate.edu/resource/weed-descriptions/), Colorado State University Extension. Accessed 2026-09-07T00:24:02+00:00. Locator: Species entries.
- **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=common-dandelion) — 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

Used in the common broad sense (T. officinale aggregate / section Ruderalia). Photographs are not intended to resolve small segregate taxa or Colorado’s native dandelions.

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 |
|---|---|---|---|---|
| common-dandelion-1 | Recognize | Species-specific | N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-2 | Plants & habitat | Species-specific | C-descriptions, N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-3 | People | Species-specific | N-taraxacum-officinale | No quantitative safe exposure established here. |
| common-dandelion-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-dandelion-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).


---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/

Content revised: 2026-09-07T02:43:00Z

Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/index.md

Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/common-dandelion/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