Cirsium occidentale var. californicum
California thistle, California Thistle
Family: Asteraceae · Type: biennial · Native
California thistle is a native biennial found in the central Sierra Nevada, southern Coast Ranges, and southwestern California in woodland, open forest, and disturbed sites at elevations below 2,300 meters. Flowering from April to July, this plant produces white to purple or rose flowers in heads 1.5 to 5 centimeters in diameter, emerging from loosely clustered inflorescences. Growing 50 to 200 centimeters tall with an erect habit, the plant has distinctively colored leaves that are green to gray on the upper surface and gray underneath. Its leaves are characterized by variable coloration and texture, ranging from nearly glabrous to cobwebby, with middle leaf segments that can vary in width and spread. The plant's involucre features phyllaries with occasional sticky-resinous ridges and tip-spines that are typically 1 to 3 millimeters long.
Habitat: Woodland, open forest, disturbed sites
Bloom period: Apr-Jul
Elevation: < 2300 m
Bioregions: SN, c&s SCoR, SW.
California counties: Los Angeles, Riverside, San Bernardino, Amador, Fresno, Kern, Madera, Mariposa, Monterey, Orange, San Diego, San Luis Obispo, Santa Barbara, Tulare, Tuolumne, Ventura, Placer, Mono, Alpine, Merced, Nevada, Santa Clara, Sierra, El Dorado, Napa, Mendocino, Siskiyou, Trinity, Contra Costa, Calaveras, Stanislaus, Lassen, Butte
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.