---
{
  "id": "common-lambsquarters",
  "name": "Common lambsquarters",
  "scientific": "Chenopodium album",
  "category": "invasive",
  "status": "Common weed; not an A/B/C listing in the reviewed state rule",
  "status_sources": [
    "CO-rules-2025"
  ],
  "warning": "Prolific garden weed; ingestion caution",
  "warning_tone": "caution",
  "aliases": [
    "white goosefoot",
    "lamb’s quarters"
  ],
  "taxonomy_note": "Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.",
  "source_ids": [
    "CO-rules-2025",
    "N-chenopodium-album",
    "C-edible-weeds",
    "S27"
  ],
  "description": "Common lambsquarters: Prolific garden weed; ingestion caution. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Recognize",
      "sources": [
        "N-chenopodium-album"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-lambsquarters-1"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "C-edible-weeds",
        "N-chenopodium-album"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-lambsquarters-2"
    },
    {
      "label": "People",
      "sources": [
        "N-chenopodium-album"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "common-lambsquarters-3"
    },
    {
      "label": "Dogs & cats",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "common-lambsquarters-4"
    },
    {
      "label": "Other animals",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "common-lambsquarters-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": "Dogs & cats",
        "question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
        "related_claim_ids": [
          "common-lambsquarters-4"
        ]
      },
      {
        "area": "Other animals",
        "question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
        "related_claim_ids": [
          "common-lambsquarters-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-lambsquarters.md"
}
---

# Common lambsquarters

*Chenopodium album*

**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)

> **Prolific garden weed; ingestion caution.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.

## Still researching this plant {#research-status}

This is a sourced working profile. Evidence is incomplete for **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.

![Chenopodium album: A broad-based, toothed leaf on an upright leafy stem.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-chenopodium-album-1.jpg)

**leaf** — A broad-based, toothed leaf on an upright leafy stem.

Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_-_3714283761.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c5/Chenopodium_album_-_3714283761.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Chenopodium album: Close view of compact, mealy green and reddish reproductive clusters along the stem.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-chenopodium-album-2.jpg)

**reproductive clusters** — Close view of compact, mealy green and reddish reproductive clusters along the stem.

Photo: Matt Lavin; [CC BY-SA 2.0](https://creativecommons.org/licenses/by-sa/2.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_-_4031382321.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/0/08/Chenopodium_album_-_4031382321.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Chenopodium album: A very young seedling with two narrow cotyledons emerging from dark soil.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-chenopodium-album-3.jpg)

**seedling** — A very young seedling with two narrow cotyledons emerging from dark soil.

Photo: Salicyna; [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0); [source record](https://commons.wikimedia.org/wiki/File:Chenopodium_album_2018-05-02_0061.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/b/b4/Chenopodium_album_2018-05-02_0061.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Chenopodium album is a difficult species complex. These images retain the source identification; the two-cotyledon seedling cannot be distinguished to species from that view alone. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.


## Recognize

An annual with variable goosefoot-shaped leaves, a whitish mealy coating on young growth and small green flower clusters. [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)

## Plants & habitat

Pueblo County Extension identifies C. album among common Colorado weeds. Many persistent seeds allow repeated emergence after disturbance. [C-edible-weeds](https://pueblo.extension.colostate.edu/early-spring-edible-plants-in-your-yard-and-garden/) [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)

## People

NC State reports digestive and nervous-system effects after large ingestion and notes oxalic acid and saponins. Food-use records are not a safe-dose recommendation. [N-chenopodium-album](https://plants.ces.ncsu.edu/plants/chenopodium-album/)

## 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-chenopodium-album** — [chenopodium album — Plant Toolbox](https://plants.ces.ncsu.edu/plants/chenopodium-album/), NC State Extension. Accessed 2026-09-07T01:21:10+00:00. Locator: Species identity, description, ecology, toxicity.
- **C-edible-weeds** — [Early Spring Edible Plants In Your Yard And Garden](https://pueblo.extension.colostate.edu/early-spring-edible-plants-in-your-yard-and-garden/), Colorado State University Extension, Pueblo County. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **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-lambsquarters) — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.

# Appendix for agents

## Open research questions

- **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

Chenopodium album is distinct from netseed lambsquarters (C. berlandieri). Exact native status within this variable complex is not resolved here.

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-lambsquarters-1 | Recognize | Species-specific | N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-2 | Plants & habitat | Species-specific | C-edible-weeds, N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-3 | People | Species-specific | N-chenopodium-album | No quantitative safe exposure established here. |
| common-lambsquarters-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| common-lambsquarters-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-lambsquarters/

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

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

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