Ceanothus divergens

Calistoga ceanothus

Family: Rhamnaceae · Type: shrub · Native

Conservation status: CNPS 1B.2

Calistoga ceanothus is a rare (CNPS 1B.2) California native shrub found in the northern Coast Ranges of Napa and Sonoma counties in volcanic slopes, chaparral, and pine/oak woodland at elevations of 150 to 950 meters. Flowering from February to April, this plant produces blue to purple flowers in compact umbel-like clusters up to 2 centimeters long. Growing as an erect or mound-like shrub 0.5 to 1.5 meters tall with ascending red-brown stems, it forms a distinctive dense and upright habit. Its opposite evergreen leaves are elliptic to narrowly obovate, 10 to 19 millimeters long, with shiny green upper surfaces and wavy margins featuring 3 to 11 spine-like teeth in the distal two-thirds. The fruit is 4 to 6 millimeters wide with slender horns 1.5 to 2.5 millimeters long.

Habitat: Volcanic slopes, chaparral, pine/oak woodland

Bloom period: Feb-Apr

Elevation: 150-950 m

Bioregions: NCoR (Napa, Sonoma cos.).

California counties: Napa, Sonoma, Lake

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.