Ceanothus tomentosus
Woolly leaf ceanothus
Photo by Chez Brungraber
Family: Rhamnaceae · Type: Shrub · Native
Ceanothus tomentosus (Woolly leaf ceanothus) is a native California shrub in the Rhamnaceae family, recognized by key diagnostic feature is dense white woolly coating on leaf undersides.
Woolly leaf ceanothus is a California native tree found in northern and central Sierra Nevada, southern California coastal areas, San Gorgonio Mountains, San Bernardino Mountains, and Peninsular Ranges in chaparral and conifer forest at elevations of 15 to 1,675 meters. Flowering from February to May, this plant produces blue to white flowers in raceme-like clusters 1.5 to 5 centimeters long. Growing occasionally tree-like with open form less than 3 meters tall, it has ascending to erect stems with flexible brown to gray-brown twigs. Its alternate leaves are elliptic to widely ovate, 10 to 25 millimeters long, dark green on top with short hairs and densely woolly underneath, featuring a glandular-serrate margin with 40 to 60 teeth. The fruit is sticky, 3 to 5 millimeters wide with three ridges and no horns.
Identification and appearance
Key characters: 25 sympatric species; key diagnostic feature is dense white woolly coating on leaf undersides
Habitat and range
Habitat: Slopes, ridges, chaparral, conifer forest
Elevation: 15-1675 m
California counties: San Diego, Riverside, Amador, El Dorado, Calaveras, Placer, Mariposa, Nevada, Butte, Ventura, Orange, San Bernardino, Siskiyou, Los Angeles, Napa, Alpine, San Luis Obispo
Outside California: northern Baja California
Bloom period
Ceanothus tomentosus blooms Feb-May.
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 tomentosus native to California?
Yes. Ceanothus tomentosus is native to California (recorded as native).
When does Ceanothus tomentosus bloom?
Ceanothus tomentosus blooms Feb-May.
Where in California does Ceanothus tomentosus grow?
Ceanothus tomentosus occurs in San Diego, Riverside, Amador, El Dorado, Calaveras, Placer, Mariposa, Nevada and other counties, at elevations of 15-1675 m.
What plant family does Ceanothus tomentosus belong to?
Ceanothus tomentosus is in the Rhamnaceae family, genus Ceanothus.
What habitat does Ceanothus tomentosus grow in?
Ceanothus tomentosus grows in Slopes, ridges, chaparral, conifer forest.
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.