Delphinium hesperium
Foothill larkspur
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Family: Ranunculaceae · Type: Herb · Native
Delphinium hesperium (Foothill larkspur) is a native California herb in the Ranunculaceae family.
Foothill larkspur is a California native perennial found in foothill and mountain regions in rocky or grassy habitats at elevations of 300 to 1,500 meters. Flowering from April to June, this plant produces deep blue to purple flowers with distinctive petal shapes, the lower petals notably hairier on their inner lobes. Growing with erect stems 40 to 80 centimeters tall and a base that is prominently ridged, it develops an upright, open structure. Its leaves are deeply divided with 3 to 14 lobes, appearing somewhat glabrous on the upper surface while softly puberulent underneath with prominent veining. The mature fruit develops 8 to 18 millimeters long, containing smooth seeds with delicate wings.
Habitat and range
California counties: Sutter, Napa, Lake, Merced, Butte, Humboldt, Santa Cruz, Solano, Alameda, Yolo, Sonoma, Marin, Contra Costa, Fresno, Mendocino, Ventura, Tulare, San Mateo, Madera, San Francisco, Santa Clara, San Benito, Siskiyou, San Luis Obispo, Colusa, Stanislaus, Trinity, Monterey, Yuba, Tehama, Plumas, Sacramento, Calaveras, Riverside, Shasta, Placer, Mariposa, El Dorado
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 native to California?
Yes. Delphinium hesperium is native to California (recorded as native).
Where in California does Delphinium hesperium grow?
Delphinium hesperium occurs in Sutter, Napa, Lake, Merced, Butte, Humboldt, Santa Cruz, Solano and other counties.
What plant family does Delphinium hesperium belong to?
Delphinium hesperium is in the Ranunculaceae family, genus Delphinium.
Related species
Other California species in the same genus, family, or bioregion.
- Delphinium hesperium subsp. cuyamacae — Cuyamaca larkspur
- Delphinium hesperium subsp. hesperium — Western larkspur
- Delphinium hesperium subsp. pallescens — Pale-flowered western larkspur
- Delphinium hutchinsoniae — Hutchinson's larkspur
- Delphinium inopinum — Unexpected larkspur
- Delphinium luteum — Golden larkspur
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.