Ceanothus megacarpus var. insularis
Island ceanothus, Island Ceanothus
(c) Steve Matson, some rights reserved (CC BY), uploaded by Steve Matson · licence
Family: Rhamnaceae · Type: Shrub · Native
Conservation status: CNPS 4.3
Ceanothus megacarpus var. insularis (Island ceanothus) is a native California shrub in the Rhamnaceae family, recognized by Only 5 sympatric species on Channel Islands; leaf arrangement differs from mainland variety.
Island ceanothus is a California native shrub found in the Channel Islands in rocky slopes, canyons, and chaparral at elevations below 475 meters. Flowering from February to March, this plant produces clusters of small white to pale blue flowers. Growing as a dense, rounded shrub 1 to 3 meters tall with multiple stems, it forms compact thickets in its coastal island habitat. Its leaves are generally opposite, with small, leathery blades that help the plant conserve moisture in its dry, exposed environment. The fruit is smooth or slightly three-ridged, typically without prominent horns.
Identification and appearance
Key characters: Only 5 sympatric species on Channel Islands; leaf arrangement differs from mainland variety
Habitat and range
Habitat: Rocky slopes, canyons, chaparral
Elevation: < 475 m
California counties: Santa Barbara, Ventura, Los Angeles
Bloom period
Ceanothus megacarpus var. insularis blooms Feb-Mar.
Conservation status
CNPS 4.3
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 megacarpus var. insularis native to California?
Yes. Ceanothus megacarpus var. insularis is native to California (recorded as native).
When does Ceanothus megacarpus var. insularis bloom?
Ceanothus megacarpus var. insularis blooms Feb-Mar.
Where in California does Ceanothus megacarpus var. insularis grow?
Ceanothus megacarpus var. insularis occurs in Santa Barbara, Ventura, Los Angeles, at elevations of < 475 m.
What plant family does Ceanothus megacarpus var. insularis belong to?
Ceanothus megacarpus var. insularis is in the Rhamnaceae family, genus Ceanothus.
Is Ceanothus megacarpus var. insularis rare or endangered?
Ceanothus megacarpus var. insularis carries California Rare Plant Rank 4.3, state rank S4.
Related species
Other California species in the same genus, family, or bioregion.
- Ceanothus megacarpus var. megacarpus — Bigpod ceanothus
- Ceanothus oliganthus — Hairy ceanothus
- Ceanothus oliganthus var. oliganthus — Hairy ceanothus
- Ceanothus oliganthus var. orcuttii — San diego hairy ceanothus
- Ceanothus oliganthus var. sorediatus — Jim brush
- Ceanothus ophiochilus — Vail lake ceanothus
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.