---
{
  "id": "black-greasewood",
  "name": "Black greasewood",
  "scientific": "Sarcobatus vermiculatus",
  "category": "native",
  "status": "Native Colorado plant · not on state Lists A/B/C",
  "status_sources": [
    "C-floristic-2020",
    "CO-rules-2025"
  ],
  "warning": "Oxalate poisoning can be fatal to livestock",
  "warning_tone": "danger",
  "aliases": [
    "greasewood"
  ],
  "taxonomy_note": "Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.",
  "source_ids": [
    "C-floristic-2020",
    "CO-rules-2025",
    "A-greasewood",
    "F-sarcobatus",
    "S27"
  ],
  "description": "Black greasewood: Oxalate poisoning can be fatal to livestock. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Identification",
      "sources": [
        "A-greasewood"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "black-greasewood-1"
    },
    {
      "label": "People",
      "sources": [
        "A-greasewood"
      ],
      "scope": "Handling precaution inferred from structure",
      "note": "",
      "id": "black-greasewood-2"
    },
    {
      "label": "Dogs & cats",
      "sources": [
        "A-greasewood"
      ],
      "scope": "Contact precaution; pet toxicology unresolved",
      "note": "",
      "id": "black-greasewood-3"
    },
    {
      "label": "Other animals",
      "sources": [
        "A-greasewood"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "black-greasewood-4"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "F-sarcobatus"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "black-greasewood-5"
    },
    {
      "label": "Management & timing",
      "sources": [
        "A-greasewood",
        "F-sarcobatus"
      ],
      "scope": "Management synthesis",
      "note": "",
      "id": "black-greasewood-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": [
          "black-greasewood-2"
        ]
      },
      {
        "area": "Dogs & cats",
        "question": "Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.",
        "related_claim_ids": [
          "black-greasewood-3"
        ]
      },
      {
        "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 78; Sarcobatus vermiculatus",
    "basis": "Included in the 2020 statewide flora assessment. This is not a current county abundance survey.",
    "source_taxon": "Sarcobatus vermiculatus"
  },
  "source": "content/plants/black-greasewood.md"
}
---

# Black greasewood

*Sarcobatus vermiculatus*

**Native Colorado plant · 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 poisoning can be fatal to livestock.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.

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

This is a sourced working profile. Evidence is incomplete for **People, Dogs & cats**. 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.

![Low, spreading greasewood shrub with dense green foliage in open dry ground.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-sarcobatus-vermiculatus-habit-322294640.jpg)

**habit** — Low, spreading greasewood shrub with dense green foliage in open dry ground.

Photo: John Gaskin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/184619764); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/322294640/original.jpg). 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.

![Close view of curved, fleshy green greasewood leaves along a pale woody twig.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-sarcobatus-vermiculatus-leaves-stem-322294623.jpg)

**leaves-stem** — Close view of curved, fleshy green greasewood leaves along a pale woody twig.

Photo: John Gaskin; [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/); [source record](https://www.inaturalist.org/observations/184619764); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/322294623/original.jpg). 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.

![Green, cylindrical greasewood flower spikes among narrow succulent leaves.](https://denson.github.io/colorado-weed-field-guide/assets/photos/coverage-range-photos-sarcobatus-vermiculatus-flower-spikes-211886879.jpg)

**flower-spikes** — Green, cylindrical greasewood flower spikes among narrow succulent leaves.

Photo: Dustin Snider; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/124972281); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/211886879/original.jpg). 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

A woody shrub of saline ground with stiff, thorn-tipped branches, narrow fleshy leaves and small pale flowers. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)

## People

Thorny branches are a contact hazard. Human ingestion safety has not been established in the reviewed material. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)

*Evidence scope: Handling precaution inferred from structure.*

## Dogs & cats

Avoid contact with sharp branches. Livestock oxalate findings do not establish a pet-specific dose or clinical outcome. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)

*Evidence scope: Contact precaution; pet toxicology unresolved.*

## Other animals

Rapid heavy consumption can cause fatal oxalate poisoning in sheep and cattle. Risk varies with season, plant chemistry and other forage; do not use this page to calculate a safe ration. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/)

## Plants & habitat

A native component of saline basins, it provides wildlife cover and browse. Dense stands require ecological assessment, not automatic treatment as an introduced invader. [F-sarcobatus](https://research.fs.usda.gov/feis/species-reviews/sarver)

## Management & timing

Ask a range specialist to assess forage access and the saline site before treatment. Existing browse value does not justify feeding an untested amount. [A-greasewood](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/) [F-sarcobatus](https://research.fs.usda.gov/feis/species-reviews/sarver)

*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.
- **A-greasewood** — [Greasewood (Sarcobatus vermiculatus)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/greasewood-sarcobatus-vermiculatus/), USDA Agricultural Research Service. Accessed 2026-09-07T02:24:50+00:00. Locator: Identification, distribution and livestock poisoning; treatment instructions excluded.
- **F-sarcobatus** — [Black greasewood](https://research.fs.usda.gov/feis/species-reviews/sarver), USDA Forest Service, Fire Effects Information System. Accessed 2026-09-07T02:24:48+00:00. Locator: Taxonomy, distribution, botanical description, wildlife/livestock values and management.
- **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=black-greasewood) — 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 78; Sarcobatus vermiculatus. 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.
- **Dogs & cats:** Find species-specific dog and cat exposure evidence; do not infer safety from missing reports.
- **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

Greasewood is also a common name for unrelated shrubs. This account is Sarcobatus vermiculatus, not creosote bush. Livestock treatment and adaptation schedules in older sources are not reproduced.

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 |
|---|---|---|---|---|
| black-greasewood-1 | Identification | Species-specific | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-2 | People | Handling precaution inferred from structure | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-3 | Dogs & cats | Contact precaution; pet toxicology unresolved | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-4 | Other animals | Species-specific | A-greasewood | No quantitative safe exposure established here. |
| black-greasewood-5 | Plants & habitat | Species-specific | F-sarcobatus | No quantitative safe exposure established here. |
| black-greasewood-6 | Management & timing | Management synthesis | A-greasewood, F-sarcobatus | 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/black-greasewood/

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

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

Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/black-greasewood/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