Delphinium californicum subsp. interius
Hospital canyon larkspur, Hospital Canyon Larkspur
Photo: parent species Delphinium californicum · no rights reserved · CC0
Family: Ranunculaceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Delphinium californicum subsp. interius (Hospital canyon larkspur) is a native California herb in the Ranunculaceae family, recognized by other californicum by flower color and habitat.
Hospital canyon larkspur is a rare (CNPS 1B.2) California native perennial found in eastern San Francisco Bay Area and south Coast Ranges in open woodland slopes at elevations of 300 to 1,000 meters. Flowering from April to June, this plant produces green-white flowers with distinctive lateral sepals 6 to 8 millimeters long and a curved spur 7 to 10 millimeters long. Growing with upright stems that are mostly smooth with puberulent pedicel tips, the plant develops an herbaceous perennial structure. Its leaves are glabrous, presenting a smooth, clean surface that contrasts with the delicate flower structure. The flower's upper petals are nearly glabrous, adding to the plant's refined botanical appearance.
Identification and appearance
Key characters: 21 sympatric species; distinguished from other californicum by flower color and habitat
Habitat and range
Habitat: Generally slopes in open woodland, eastern side of coast ranges
Elevation: 300-1000 m
California counties: Alameda, San Joaquin, Santa Clara, Contra Costa, Merced, San Benito, Monterey
Bloom period
Delphinium californicum subsp. interius blooms Apr-Jun.
Conservation status
CNPS 1B.2
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 californicum subsp. interius native to California?
Yes. Delphinium californicum subsp. interius is native to California (recorded as native).
When does Delphinium californicum subsp. interius bloom?
Delphinium californicum subsp. interius blooms Apr-Jun.
Where in California does Delphinium californicum subsp. interius grow?
Delphinium californicum subsp. interius occurs in Alameda, San Joaquin, Santa Clara, Contra Costa, Merced, San Benito, Monterey, at elevations of 300-1000 m.
What plant family does Delphinium californicum subsp. interius belong to?
Delphinium californicum subsp. interius is in the Ranunculaceae family, genus Delphinium.
Is Delphinium californicum subsp. interius rare or endangered?
Delphinium californicum subsp. interius carries California Rare Plant Rank 1B.2, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.