Castilleja densiflora subsp. densiflora
Photo: parent species Castilleja densiflora · no rights reserved · CC0
Family: Orobanchaceae · Type: Herb · Native
Castilleja densiflora subsp. densiflora is a native California herb in the Orobanchaceae family, recognized by dense rose-purple clusters distinctive.
Dense-flowered owl's clover is a California native annual herb found in northern Coast Ranges, Sierra Nevada foothills, San Francisco Bay Area, and southern Coast Ranges in grassland habitats at elevations below 1,600 meters. Flowering from March to May, this plant produces rose-purple flowers with cream-colored bracts that closely resemble the flowers themselves. Growing with slender stems reaching 10 to 30 centimeters tall, it forms compact, dense inflorescences. Its leaves are narrow and linear, arranged alternately along the stem, blending into the plant's delicate structure. The flower's distinctive calyx ranges from 8 to 20 millimeters long, with a lower lip that gradually widens and subtle teeth approximately 2 millimeters in length.
Identification and appearance
Key characters: 25 sympatric species, dense rose-purple clusters distinctive
Habitat and range
Habitat: Grassland
Elevation: < 1600 m
California counties: Riverside, Monterey, Sonoma, Ventura, Marin, Contra Costa, San Mateo, Placer, Alameda, Napa, San Luis Obispo, Tuolumne, El Dorado, San Francisco, Santa Cruz, Mendocino, Santa Clara, Santa Barbara, Solano, Lake, San Diego, Amador, Calaveras, Tulare, Mariposa, Kern, Fresno
Bloom period
Castilleja densiflora subsp. densiflora blooms Mar-May.
How to tell it apart
vs Triphysaria: Castilleja lacks the sharp fold in flower throat; Triphysaria has abrupt crease above lower lip.; vs Trifolium: Castilleja has tubular flowers with colorful bracts; Trifolium has round heads of pea-like flowers and three leaflets.; vs Pedicularis: Castilleja has open forward beak and colorful bracts; Pedicularis has closed hood and fern-like leaves.; vs Orthocarpus: Castilleja has open beak you can see into; Orthocarpus has closed hood covering stamens completely.; vs Epilobium: Castilleja has tubular two-lipped flowers and colorful bracts; Epilobium has four separate petals arranged in cross.
Frequently asked questions
Is Castilleja densiflora subsp. densiflora native to California?
Yes. Castilleja densiflora subsp. densiflora is native to California (recorded as native).
When does Castilleja densiflora subsp. densiflora bloom?
Castilleja densiflora subsp. densiflora blooms Mar-May.
Where in California does Castilleja densiflora subsp. densiflora grow?
Castilleja densiflora subsp. densiflora occurs in Riverside, Monterey, Sonoma, Ventura, Marin, Contra Costa, San Mateo, Placer and other counties, at elevations of < 1600 m.
What plant family does Castilleja densiflora subsp. densiflora belong to?
Castilleja densiflora subsp. densiflora is in the Orobanchaceae family, genus Castilleja.
What habitat does Castilleja densiflora subsp. densiflora grow in?
Castilleja densiflora subsp. densiflora grows in Grassland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-08
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.