Ceanothus maritimus
Maritime ceanothus
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Family: Rhamnaceae · Type: Shrub · Native
Conservation status: CNPS 1B.2
Ceanothus maritimus (Maritime ceanothus) is a native California shrub in the Rhamnaceae family, recognized by opposite leaves and coastal habitat distinctive.
Maritime ceanothus is a rare (CNPS 1B.2) California native shrub found in the northwestern San Luis Obispo County coastal hills and bluffs at elevations below 60 meters. Flowering from February to May, this plant produces blue flowers in compact umbel-like clusters less than 2 centimeters wide. Growing as a low, spreading or ascending shrub generally less than 1 meter tall, it forms a mat- to mound-like shape with distinctive red-brown twigs. Its evergreen leaves are obovate or oblong-obovate, 8 to 20 millimeters long, with a shiny green upper surface and gray-tomentose underside, featuring a truncate or notched tip and occasionally having 3 to 5 teeth near the end. The fruit is wrinkled near the top, measuring 5 to 8 millimeters long with small horns 1 to 2 millimeters in length.
Identification and appearance
Key characters: 21 sympatric species; opposite leaves and coastal habitat distinctive
Habitat and range
Habitat: Coastal hills, bluffs
Elevation: < 60 m
California counties: San Luis Obispo, Yolo
Bloom period
Ceanothus maritimus blooms Feb-May.
Conservation status
CNPS 1B.2
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 maritimus native to California?
Yes. Ceanothus maritimus is native to California (recorded as native).
When does Ceanothus maritimus bloom?
Ceanothus maritimus blooms Feb-May.
Where in California does Ceanothus maritimus grow?
Ceanothus maritimus occurs in San Luis Obispo, Yolo, at elevations of < 60 m.
What plant family does Ceanothus maritimus belong to?
Ceanothus maritimus is in the Rhamnaceae family, genus Ceanothus.
Is Ceanothus maritimus rare or endangered?
Ceanothus maritimus carries California Rare Plant Rank 1B.2, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
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.