Centaurea calcitrapa

Purple star-thistle

Family: Asteraceae · Type: perennial · Not Native

Conservation status: Cal-IPC Yes

Purple star-thistle is a naturalized perennial herb found in northwestern California, southern California Ranges, Sierra Nevada Foothills, northern Sierra Nevada, Central Valley, central western, and southwestern California in pastures and disturbed places at elevations generally below 1,000 meters. Flowering from April to November, this plant produces distinctive purple flowers with spiny-fringed involucre bracts and sharp tip-spines 10 to 25 millimeters long. Growing 2 to 10 meters tall with a bushy, often mounded appearance, the plant has wide-spreading stems that branch throughout. Its leaves range from deeply divided basal leaves 10 to 20 centimeters long to narrow, sessile cauline leaves that can be entire, toothed, or divided into slender lobes. The plant forms dense, prickly clusters with lance-linear bracts surrounding each flower head, creating a distinctive and formidable appearance in disturbed landscapes.

Habitat: Pastures, disturbed places

Bloom period: Apr-Nov

Elevation: generally < 1000 m

Bioregions: NW, s CaRF, SNF, n SNH, GV, CW, SW

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