Cirsium occidentale var. coulteri
Coulter's thistle
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Family: Asteraceae · Type: Biennial · Native
Cirsium occidentale var. coulteri (Coulter's thistle) is a native California biennial in the Asteraceae family, recognized by needle-like, equal phyllaries are key feature.
Coulter's thistle is a California native biennial found in coastal California regions including the Central Coast, Southern Coast, and Channel Islands in grasslands, dunes, oak woodlands, and scrub at elevations generally below 700 meters. Flowering from March to June, this plant produces light purple to rich red-purple flowers in large heads approximately 4 to 5 centimeters in diameter, creating striking displays across its native habitats. Growing erect or bushy with variable tomentose texture, the plant reaches heights of 30 to 150 centimeters with densely cobwebby involucres. Its distinctive leaves are needle-like, with phyllaries extending 13 to 30 millimeters long and arranged in ascending to stiffly spreading patterns. The corolla, measuring 25 to 33 millimeters, contributes to its dramatic and eye-catching appearance in coastal and inland landscapes.
Identification and appearance
Key characters: 14 sympatric species; needle-like, equal phyllaries are key feature
Habitat and range
Habitat: Grassland, dunes, oak woodland, scrub
Elevation: generally < 700 m
Bloom period
Cirsium occidentale var. coulteri blooms Mar-Jun.
How to tell it apart
vs Carduus: Cirsium has fluffy, feathery seed tufts; Carduus has rough bristles or no pappus and continuous spiny wings down the stem.; vs Silybum: Cirsium leaves are plain green; Silybum has bright white marbling along the leaf veins.; vs Sonchus: Cirsium has thistle-type flowers with spine-tipped bracts; Sonchus has dandelion-like flowers and milky sap.; vs Cynara: Cirsium heads are 1-6 cm across; Cynara heads are massive (4-15 cm, tennis ball sized) with fleshy bases.; vs Centaurea: Cirsium has linear bracts without appendages; Centaurea bracts have fringed or comb-like tips.
Frequently asked questions
Is Cirsium occidentale var. coulteri native to California?
Yes. Cirsium occidentale var. coulteri is native to California (recorded as native).
When does Cirsium occidentale var. coulteri bloom?
Cirsium occidentale var. coulteri blooms Mar-Jun.
What plant family does Cirsium occidentale var. coulteri belong to?
Cirsium occidentale var. coulteri is in the Asteraceae family, genus Cirsium.
What habitat does Cirsium occidentale var. coulteri grow in?
Cirsium occidentale var. coulteri grows in Grassland, dunes, oak woodland, scrub.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.