Carduus pycnocephalus subsp. pycnocephalus

Italian thistle, Italian Thistle

Family: Asteraceae · Type: annual · Not Native

Conservation status: Cal-IPC Yes

Italian thistle is a naturalized annual found in the Klamath Ranges, northern California Coast Ranges, Cascade Range foothills, Sierra Nevada foothills, Sacramento Valley, central western California, southern California coast, Transverse Ranges, and Peninsular Ranges in roadsides, pastures, and disturbed areas at elevations below 1,200 meters. Flowering from March to July, this plant produces pink to purple flowers in dense clustered heads 1 to 2 centimeters in diameter with lance-linear spiny tips. Growing 20 to 200 centimeters tall with narrowly spiny-winged stems that are glabrous or slightly woolly, it forms prominent clusters of thistle-like growth. Its basal leaves are 10 to 15 centimeters long with 4 to 10 distinctive lobes, while cauline leaves are somewhat woolly. The fruit is 4 to 6 millimeters long, golden to brown, with prominent veins and a pappus 10 to 15 millimeters in length.

Habitat: Roadsides, pastures, disturbed areas

Bloom period: Mar-Jul

Elevation: < 1200 m

Bioregions: KR, NCoR, CaRF, SNF, ScV, CW, SCo, TR, PR

California counties: Kern, San Diego, Calaveras, Marin, Los Angeles, Butte, Yuba, Colusa, Contra Costa, Amador, Santa Clara, Alameda, Sonoma, San Francisco, Santa Barbara, Solano, Shasta, Tehama, Humboldt, San Luis Obispo, Mendocino, Trinity, San Mateo, Napa, Ventura, Riverside, Monterey, Placer, Siskiyou, Lake, Yolo, Sutter, El Dorado, Santa Cruz

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