Ceanothus arcuatus
Arching ceanothus
(c) Steve Matson, some rights reserved (CC BY) · licence
Family: Rhamnaceae · Type: Shrub · Native
Ceanothus arcuatus (Arching ceanothus) is a native California shrub in the Rhamnaceae family, recognized by . Small opposite leaves with entire margins diagnostic among northern species.
Arching ceanothus is a California native shrub found in the Klamath Ranges, northern Coast Ranges, southern Cascade Ranges, and northern Sierra Nevada Mountains on open rocky slopes and in montane forest at elevations of 580 to 2,140 meters. Flowering from April to June, this plant produces white to light blue flowers in compact umbel-like clusters less than 1.5 centimeters long. Growing as a dense, mound-like shrub 30 to 100 centimeters tall with spreading to ascending brown to gray-brown stems, it forms a compact and intricate growth habit. Its opposite evergreen leaves are small, measuring 7 to 12 millimeters long and 2 to 5 millimeters wide, with elliptic to obovate shapes and dull green surfaces. The fruit is a white, slightly three-ridged capsule about 4 to 6 millimeters long with slender horns 1.5 to 2 millimeters long.
Identification and appearance
Key characters: 34 sympatric species. Small opposite leaves with entire margins diagnostic among northern species.
Habitat and range
Habitat: Open rocky slopes, montane forest
Elevation: 580-2140 m
California counties: Humboldt, Trinity, Del Norte, El Dorado, Madera, Plumas, Siskiyou, Sierra, Shasta, Tuolumne, Tehama, Calaveras, Mendocino, Placer, Mariposa
Outside California: Oregon
Bloom period
Ceanothus arcuatus blooms Apr-Jun.
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 arcuatus native to California?
Yes. Ceanothus arcuatus is native to California (recorded as native).
When does Ceanothus arcuatus bloom?
Ceanothus arcuatus blooms Apr-Jun.
Where in California does Ceanothus arcuatus grow?
Ceanothus arcuatus occurs in Humboldt, Trinity, Del Norte, El Dorado, Madera, Plumas, Siskiyou, Sierra and other counties, at elevations of 580-2140 m.
What plant family does Ceanothus arcuatus belong to?
Ceanothus arcuatus is in the Rhamnaceae family, genus Ceanothus.
What habitat does Ceanothus arcuatus grow in?
Ceanothus arcuatus grows in Open rocky slopes, montane forest.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.