---
{
  "id": "tall-larkspur",
  "name": "Tall larkspur",
  "scientific": "Delphinium barbeyi",
  "category": "native",
  "status": "Native Colorado wildflower; grazing and ingestion hazard",
  "status_sources": [
    "C-routt-guide"
  ],
  "warning": "Serious livestock and pet poisoning hazard",
  "warning_tone": "danger",
  "aliases": [
    "Barbey’s larkspur"
  ],
  "taxonomy_note": "This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.",
  "source_ids": [
    "C-routt-guide",
    "ARS-larkspur",
    "A-larkspur",
    "S27"
  ],
  "description": "Tall larkspur: Serious livestock and pet poisoning hazard. Identification and evidence for Colorado readers.",
  "claim_evidence": [
    {
      "label": "Recognize",
      "sources": [
        "ARS-larkspur"
      ],
      "scope": "Larkspur-group morphology; use a species key",
      "note": "",
      "id": "tall-larkspur-1"
    },
    {
      "label": "Plants & habitat",
      "sources": [
        "C-routt-guide"
      ],
      "scope": "Species-specific",
      "note": "",
      "id": "tall-larkspur-2"
    },
    {
      "label": "People",
      "sources": [],
      "scope": "Review limitation",
      "note": "",
      "id": "tall-larkspur-3"
    },
    {
      "label": "Dogs & cats",
      "sources": [
        "A-larkspur"
      ],
      "scope": "Genus-level warning; no species-specific pet threshold",
      "note": "",
      "id": "tall-larkspur-4"
    },
    {
      "label": "Other animals",
      "sources": [
        "ARS-larkspur"
      ],
      "scope": "Larkspur-group evidence",
      "note": "",
      "id": "tall-larkspur-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": [
          "tall-larkspur-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"
  },
  "source": "content/plants/tall-larkspur.md"
}
---

# Tall larkspur

*Delphinium barbeyi*

**Native Colorado wildflower; grazing and ingestion hazard.** [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)

> **Serious livestock and pet poisoning hazard.** [Exposure help](https://denson.github.io/colorado-weed-field-guide/safety/).

**Identification caveat:** This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.

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

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

![Delphinium barbeyi: A blue-flowered larkspur stem with several spurred flowers and divided stem leaves.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-delphinium-barbeyi-1.jpg)

**flowering stem** — A blue-flowered larkspur stem with several spurred flowers and divided stem leaves.

Photo: Ms. Sticky; [CC BY 2.0](https://creativecommons.org/licenses/by/2.0); [source record](https://commons.wikimedia.org/wiki/File:Delphinium_barbeyi.jpg); [original image](https://upload.wikimedia.org/wikipedia/commons/6/68/Delphinium_barbeyi.jpg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. Wikimedia server-resized derivative; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Delphinium barbeyi: Several tall purple-flowered stems rising above leafy subalpine vegetation, with a mountain slope behind.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-delphinium-barbeyi-2.jpg)

**habit and habitat** — Several tall purple-flowered stems rising above leafy subalpine vegetation, with a mountain slope behind.

Photo: John Powers; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/66494294); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/107202729/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.

![Delphinium barbeyi: Side view of deep purple flowers showing elongated backward-pointing spurs and fine hairs.](https://denson.github.io/colorado-weed-field-guide/assets/photos/additional-problem-photos-delphinium-barbeyi-3.jpg)

**flower detail** — Side view of deep purple flowers showing elongated backward-pointing spurs and fine hairs.

Photo: John Powers; [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/); [source record](https://www.inaturalist.org/observations/66494294); [original image](https://inaturalist-open-data.s3.amazonaws.com/photos/107202638/original.jpeg). Source scientific identification plus visual morphology review of the selected photograph. This is a source-identified reference, not a specimen-based taxonomic determination. Identification follows the exact source species. Other tall larkspurs can resemble this species, and a reference photo alone cannot establish livestock risk for an unknown plant. iNaturalist large server-resized photo; no crop, colour change or generative editing. Gallery display preserves the full image; the catalog preview uses a CSS crop.


## Recognize

Tall larkspurs bear clusters of blue spurred flowers above deeply lobed leaves. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)

*Evidence scope: Larkspur-group morphology; use a species key.*

## Plants & habitat

Routt County records tall larkspur on higher-elevation slopes and in aspen habitats. [C-routt-guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf)

## 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

ASPCA lists Delphinium species as toxic to dogs and cats. Alkaloids can disrupt nerve and muscle function; suspected ingestion needs prompt veterinary attention. [A-larkspur](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur)

*Evidence scope: Genus-level warning; no species-specific pet threshold.*

## Other animals

Larkspur is a major cattle-poisoning concern. All parts are toxic; severity varies with species, growth stage and conditions. [ARS-larkspur](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/)

*Evidence scope: Larkspur-group evidence.*

## 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-routt-guide** — [Routt County Weed Identification Guide](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2021/06/RC_Weed_Guide_2021.pdf), Routt County / Colorado State University Extension. Accessed 2026-09-07T01:14:14+00:00. Locator: Common weeds and poisonous plants; 2021 edition.
- **ARS-larkspur** — [Larkspur (Delphinium spp.)](https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/), USDA Agricultural Research Service. Accessed 2026-09-07T01:34:00+00:00. Locator: Species descriptions, occurrence and hazard sections; food preparation and treatment instructions not adopted.
- **A-larkspur** — [Larkspur — Delphinium species](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/larkspur), ASPCA Poison Control. 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=tall-larkspur) — 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.
- **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

This profile focuses on Delphinium barbeyi. Other larkspurs differ in appearance and alkaloid content. Genus-level pet warnings are clearly marked; cattle exposure amounts are not transferred to pets.

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 |
|---|---|---|---|---|
| tall-larkspur-1 | Recognize | Larkspur-group morphology; use a species key | ARS-larkspur | No quantitative safe exposure established here. |
| tall-larkspur-2 | Plants & habitat | Species-specific | C-routt-guide | No quantitative safe exposure established here. |
| tall-larkspur-3 | People | Review limitation | Review limitation | No quantitative safe exposure established here. |
| tall-larkspur-4 | Dogs & cats | Genus-level warning; no species-specific pet threshold | A-larkspur | No quantitative safe exposure established here. |
| tall-larkspur-5 | Other animals | Larkspur-group evidence | ARS-larkspur | 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/tall-larkspur/

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

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

Text fallback: https://denson.github.io/colorado-weed-field-guide/plants/tall-larkspur/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