Delphinium hesperium subsp. hesperium
Western larkspur, Western Larkspur
Photo: parent species Delphinium hesperium · no rights reserved · CC0
Family: Ranunculaceae · Type: Herb · Native
Delphinium hesperium subsp. hesperium (Western larkspur) is a native California herb in the Ranunculaceae family, recognized by wide petals and sparse flower arrangement.
Western larkspur is a native perennial found in northwestern California and San Francisco Bay Area regions in oak woodlands and coastal ranges at elevations of 10 to 1,100 meters. Flowering from March to June, this plant produces dark blue-purple flowers with spreading sepals 8 to 16 millimeters long and a distinctive curved spur 10 to 18 millimeters in length. Growing with stems that range from nearly smooth to slightly hairy at the base, it develops inflorescences with flowers typically less than 30 in number. Its lower petal blades are relatively small, measuring 5 to 8 millimeters long, with pedicels generally spaced more than 8 millimeters apart. The plant's compact growth and rich blue-purple coloration make it a distinctive feature of coastal oak woodland landscapes.
Identification and appearance
Key characters: 24 sympatric species; distinguished by wide petals and sparse flower arrangement
Habitat and range
Habitat: Oak woodland, western slope coast ranges
Elevation: 10-1100 m
California counties: Contra Costa, San Benito, Lake, San Luis Obispo, Shasta, Sacramento, Butte, Tehama, Humboldt, Sonoma, Marin, Santa Clara, Mendocino, Napa, San Mateo, Monterey, Fresno
Bloom period
Delphinium hesperium subsp. hesperium blooms Mar-Jun.
How to tell it apart
vs Lupinus: Delphinium has backward-pointing spurs on flowers; Lupinus has pea-family flowers with banner-wing-keel structure.; vs Geranium: Delphinium has spurred bilateral flowers; Geranium has radially symmetric 5-petaled flowers with no spur.; vs Epilobium: Delphinium has spurred flowers and palmately divided leaves; Epilobium has unspurred 4-petaled flowers and simple or opposite leaves.; vs Aquilegia: Delphinium has a single spur per flower; Aquilegia has 5 spurs radiating from the center.; vs Aconitum: Delphinium has an open spur with visible stamens; Aconitum has a closed hood hiding the stamens.
Frequently asked questions
Is Delphinium hesperium subsp. hesperium native to California?
Yes. Delphinium hesperium subsp. hesperium is native to California (recorded as native).
When does Delphinium hesperium subsp. hesperium bloom?
Delphinium hesperium subsp. hesperium blooms Mar-Jun.
Where in California does Delphinium hesperium subsp. hesperium grow?
Delphinium hesperium subsp. hesperium occurs in Contra Costa, San Benito, Lake, San Luis Obispo, Shasta, Sacramento, Butte, Tehama and other counties, at elevations of 10-1100 m.
What plant family does Delphinium hesperium subsp. hesperium belong to?
Delphinium hesperium subsp. hesperium is in the Ranunculaceae family, genus Delphinium.
What habitat does Delphinium hesperium subsp. hesperium grow in?
Delphinium hesperium subsp. hesperium grows in Oak woodland, western slope coast ranges.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.