Ceanothus oliganthus
Hairy ceanothus
Photo by Chez Brungraber
Family: Rhamnaceae · Type: Shrub · Native
Ceanothus oliganthus (Hairy ceanothus) is a native California shrub in the Rhamnaceae family, recognized by numerous minute glandular teeth and potential tree form distinctive.
Hairy ceanothus is a California native tree found in coastal and southern California in chaparral and woodland habitats. Flowering from March to June, this plant produces blue to purple-blue flowers in compact raceme-like clusters 1 to 5 centimeters long. Growing as an open, erect tree up to 3.5 meters tall with flexible twigs, it has a distinctive branching structure. Its alternate, evergreen leaves are ovate to elliptic, 11 to 30 millimeters long, dark green on top, paler underneath, with 20 to 70 tiny gland-like teeth along the margins. The fruit is sticky, 4 to 7 millimeters wide, with a slightly ridged or bulged surface.
Identification and appearance
Key characters: 65 sympatric species; numerous minute glandular teeth and potential tree form distinctive
Habitat and range
California counties: San Diego, Ventura, Orange, Riverside, Los Angeles, Solano, Monterey, Santa Barbara, Kern, San Mateo, San Luis Obispo, San Bernardino, Nevada, Placer, Humboldt, Marin, Tulare, Madera, San Benito, Napa, Yolo, Alameda, Contra Costa
How to tell it apart
vs Rhamnus: Ceanothus has showy blue/white/pink flowers in dense clusters; Rhamnus has tiny inconspicuous greenish flowers.; vs Quercus: Ceanothus has showy flower clusters and small leaves; Quercus has acorns and distinctive lobed or toothed oak leaves.; vs Baccharis: Ceanothus has individual flowers with 5 separate petals; Baccharis has composite flower heads with tiny disc flowers.; vs Cercocarpus: Ceanothus has blue/white/pink flowers in clusters; Cercocarpus has tiny flowers with no petals and feathery fruiting tails.; vs Adenostoma: Ceanothus flowers have 5 distinct colored petals; Adenostoma has tiny white flowers and needle-like clustered leaves.
Frequently asked questions
Is Ceanothus oliganthus native to California?
Yes. Ceanothus oliganthus is native to California (recorded as native).
Where in California does Ceanothus oliganthus grow?
Ceanothus oliganthus occurs in San Diego, Ventura, Orange, Riverside, Los Angeles, Solano, Monterey, Santa Barbara and other counties.
What plant family does Ceanothus oliganthus belong to?
Ceanothus oliganthus is in the Rhamnaceae family, genus Ceanothus.
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.