---
{
  "id": "wild-proso-millet",
  "name": "Wild proso millet",
  "scientific": "Panicum miliaceum",
  "category": "invasive",
  "status": "Colorado noxious weed · List C — Manage widespread weeds",
  "status_sources": [
    "CO-rules-2025"
  ],
  "warning": "Seed contamination and crop competition",
  "warning_tone": "caution",
  "aliases": [
    "proso millet",
    "broomcorn millet"
  ],
  "taxonomy_note": "Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.",
  "source_ids": [
    "CO-rules-2025",
    "K-wild-proso",
    "S27",
    "Fremont-list-definitions"
  ],
  "description": "Wild proso millet: Seed contamination and crop competition. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Recognize",
      "sources": [
        "K-wild-proso"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "wild-proso-millet-1"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "K-wild-proso"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "wild-proso-millet-2"
    },
    {
      "label": "People",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "wild-proso-millet-3"
    },
    {
      "label": "Dogs & cats",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "wild-proso-millet-4"
    },
    {
      "label": "Other animals",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "wild-proso-millet-5"
    },
    {
      "id": "wild-proso-millet-list-meaning",
      "label": "State-list meaning",
      "sources": [
        "Fremont-list-definitions"
      ],
      "scope": "Colorado management-category definition; species classification retains its original status sources",
      "note": "Plain-language editorial label for a management category; not a toxicity or danger rating.",
      "reviewed": "2026-09-07"
    }
  ],
  "noxious_class": "C",
  "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": [
          "wild-proso-millet-3"
        ]
      },
      {
        "area": "Dogs & cats",
        "question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
        "related_claim_ids": [
          "wild-proso-millet-4"
        ]
      },
      {
        "area": "Other animals",
        "question": "Clarify feeding and exposure risks for each animal group; do not transfer findings between species.",
        "related_claim_ids": [
          "wild-proso-millet-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"
  },
  "noxious_class_label": "C — Manage widespread weeds",
  "source": "content/plants/wild-proso-millet.md"
}
---

# Wild proso millet

*Panicum miliaceum*

**Colorado noxious weed · List C — Manage widespread weeds.** [CO-rules-2025](https://www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=11948&fileName=8+CCR+1206-2)

Widespread and well established. Control is recommended by the state; local governments may require management. This is a management category, separate from danger ratings. [Category source](https://fremontcountyco.gov/weed-control/weed-identification) · [What the lists mean](https://denson.github.io/colorado-weed-field-guide/safety/#weed-lists).

> **Seed contamination and crop competition.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.

## 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.

![Panicum miliaceum: Pale mature grains hang along densely branched drooping panicles.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-panicum-miliaceum-14-03-grain.jpg)

**grain** — Pale mature grains hang along densely branched drooping panicles.

Photo: Kurt Stüber; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/); [source record](https://commons.wikimedia.org/wiki/File:Panicum_miliaceum0.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/a/a4/Panicum_miliaceum0.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. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Panicum miliaceum: Upright leafy grass stems with loose drooping panicles.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-panicum-miliaceum-14-06-habit.jpg)

**habit** — Upright leafy grass stems with loose drooping panicles.

Photo: Dalgial; [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0); [source record](https://commons.wikimedia.org/wiki/File:Panicum_miliaceum.JPG); [original image](https://upload.wikimedia.org/wikipedia/commons/f/f6/Panicum_miliaceum.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. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. Wikimedia server-resized derivative; no crop, color change, or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Panicum miliaceum: Hairy green leaf sheath and culm node photographed with a 10 mm scale.](https://denson.github.io/colorado-weed-field-guide/assets/photos/common-priority-photos-panicum-miliaceum-14-09-leaf-sheath.jpg)

**leaf-sheath** — Hairy green leaf sheath and culm node 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:Panicum_miliaceum_subsp._miliaceum_sl1.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/c/c7/Panicum_miliaceum_subsp._miliaceum_sl1.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. Cultivated and feral proso-millet forms differ. Source photographs include named P. miliaceum subsp. miliaceum; they do not establish a weedy biotype or cultivar. 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

An annual grass with hairy leaf sheaths and a branched panicle that may remain partly enclosed by the upper sheath. [K-wild-proso](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet)

## Plants & habitat

Weedy biotypes compete in crops and spread with contaminated seed or machinery. Prevent seed movement between fields. [K-wild-proso](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet)

## 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. 

## 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.
- **K-wild-proso** — [Wild-proso millet](https://cals.cornell.edu/weed-science/weed-profiles/wild-proso-millet), Cornell University College of Agriculture and Life Sciences. Accessed 2026-09-07T01:16:19+00:00. Locator: Species identity, description, ecological and exposure evidence; verify group scope.
- **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=wild-proso-millet) — 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

Cultivated proso and wild proso belong to the same species. These species-reference photographs include cultivated settings and do not demonstrate a wild, shattering or herbicide-resistant biotype. Seed and field-history assessment is needed.

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 |
|---|---|---|---|---|
| wild-proso-millet-1 | Recognize | Species-specific | K-wild-proso | No quantitative safe exposure established here. |
| wild-proso-millet-2 | Plants & habitat | Species-specific | K-wild-proso | No quantitative safe exposure established here. |
| wild-proso-millet-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-proso-millet-4 | Dogs & cats | Review limitation | Review limitation | No quantitative safe exposure established here. |
| wild-proso-millet-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).

## State-list label provenance

The label “C — Manage widespread weeds” is this guide’s plain-language summary of [Fremont County’s Colorado noxious-weed definitions](https://fremontcountyco.gov/weed-control/weed-identification) [Fremont-list-definitions]. The letter and species assignment retain the status sources above. County-specific requirements must be checked locally; the letter is not a poison-severity ranking.


---
Canonical HTML: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/

Content revised: 2026-09-07T03:50:00Z

Markdown mirror: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/index.md

Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/wild-proso-millet/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