Cirsium rhothophilum

Surf thistle

Family: Asteraceae · Type: perennial · Native

Conservation status: CNPS 1B.2

Surf thistle is a rare (CNPS 1B.2) California native perennial found in southern coastal California in San Luis Obispo and northern Santa Barbara counties on coastal dunes and bluffs at elevations below 20 meters. Flowering from April to August, this plant produces white to pale yellow flowers in heads 3 to 4 centimeters wide, clustered closely among the plant's upper leaves. Growing with 1 to several stems 10 to 100 centimeters tall, it forms a distinctive bush-like or low mounded shape completely covered in dense gray felt-like hairs. Its strongly wavy leaves are densely gray or white-felted, with lower leaves up to 25 centimeters long, wing-petioled, and having spines 1 to 4 millimeters long. The plant's upper leaves become progressively more lobed and spinier, creating a distinctive architectural form characteristic of coastal dune environments.

Habitat: Dunes, bluffs

Bloom period: Apr-Aug

Elevation: < 20 m

Bioregions: s CCo (s San Luis Obispo, n Santa Barbara cos.).

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