Carduus tenuiflorus

Italian thistle

Family: Asteraceae · Type: annual · Not Native

Conservation status: Cal-IPC Yes

Italian thistle is a naturalized annual found in northern coastal, northern coastal ranges, Sierra Nevada foothills, central western, and southwestern California in roadsides, pastures, and disturbed areas at elevations below 1,000 meters. Flowering from April to June, this plant produces pink to purple flowers in clusters of 5 to 20 heads up to 2 centimeters in diameter. Growing with stems 20 to 200 centimeters tall that are widely spiny-winged and either glabrous or slightly woolly, it forms an extensive and aggressive growth habit. Its basal leaves are 10 to 15 centimeters long with 12 to 20 deep lobes, while cauline leaves are slightly tomentose. The fruit is brown, 4 to 5 millimeters long with 10 to 13 prominent veins and a pappus 10 to 15 millimeters in length.

Habitat: Roadsides, pastures, disturbed areas

Bloom period: Apr-Jun

Elevation: < 1000 m

Bioregions: NCo, NCoR, SNF, 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.