Tall larkspur
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Delphinium barbeyi
Native Colorado wildflower; grazing and ingestion hazard. C-routt-guide
Serious livestock and pet poisoning hazard. Exposure help.
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
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.
Ms. Sticky · CC BY 2.0
Photo source and identification
Original record · Original image
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.
John Powers · CC BY 4.0
Photo source and identification
Original record · Original image
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.
John Powers · CC BY 4.0
Photo source and identification
Original record · Original image
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
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
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
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
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
References
- C-routt-guide — Routt County Weed Identification Guide, 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.), 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, 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, PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.