Flower profile
Columbian larkspur
Delphinium trolliifolium
Columbian larkspur is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Oregon it's most often seen in bloom in April–June.
*iNaturalist research-grade observations, as of October 17, 2026.
On our lists for: Oregon
Quick look
Delphinium trolliifolium is a species of larkspur known by the common names poison delphinium, cow poison, and Columbian larkspur. It is native to Washington, Oregon, and northern California. This wildflower reaches one half to just over one meter in height. It has large, shiny, deeply lobed leaves.
- It belongs to the Ranunculaceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
- USDA PLANTS lists it as native in the lower 48 states and records it in 2 states. USDA PLANTS
- NatureServe lists it as native to Oregon. NatureServe
- In Oregon, most iNaturalist sightings of it in flower come in April–June. iNaturalist
- iNaturalist has 2,046 research-grade sightings of it in Oregon, ranking #85 among the 110 flowers on our Oregon list. iNaturalist
Columbian larkspur gift ideas
Handmade columbian larkspur gifts from independent makers.
🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.
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Columbian larkspur art print
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Columbian larkspur greeting card
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Columbian larkspur mug
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Columbian larkspur earrings
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Columbian larkspur embroidery pattern
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Columbian larkspur sticker
When does it bloom?
In Oregon, most flowering sightings come in April–June.
Conservation status
- Federal (U.S. ESA)
- Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
- NatureServe global
- G3 Vulnerable worldwide. NatureServe
- Oregon
- Not listed Not on Oregon endangered and threatened plants (OAR 603-073-0070). NatureServe: SNR, not yet ranked in Oregon. OAR 603-073-0070
- Rare elsewhere
- No other U.S. state ranks it S1, S2, SH or SX.
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.
ASPCA's entry “Larkspur” (Delphinium species), which covers the whole genus, lists it as toxic to dogs, cats and horses. Signs include: Unless there is a lack of suitable forage, horses typically do not consume toxic amounts of larkspur. The toxicity of the plant may vary depending on seasonal changes and field conditions; as the… ASPCA
🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.
Where does it grow?
USDA PLANTS records columbian larkspur in 2 states.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
California, Oregon.
Oregon counties with USDA records: Benton, Clatsop, Columbia, Coos, Curry, Douglas, Hood River, Jackson, Lane, Lincoln, Linn, Marion, Multnomah, Polk, Tillamook, Yamhill.
More Oregon flowers
Sources
- USDA, NRCS. PLANTS Database, profile DETR2.
- iNaturalist, Delphinium trolliifolium: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Delphinium trolliifolium (lead quoted under CC BY-SA 4.0).
- Oregon: Oregon endangered and threatened plants (OAR 603-073-0070).
- Oregon: Oregon noxious weed quarantine, A and B weeds (OAR 603-052-1200).
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Delphinium trolliifolium (global and state ranks).
- Edibility and toxicity: ASPCA.
- Photo: Alex Abair via iNaturalist · CC BY 4.0 · resized.