Silybum marianum

Blessed milkthistle

Family: Asteraceae · Type: annual · Not Native

Conservation status: Cal-IPC Yes

Blessed milkthistle is a naturalized annual found in northern coastal California, northern Coast Ranges, northeastern Sierra Nevada foothills, Central Valley, central western California, and southwestern California in disturbed areas like roadsides and pastures at elevations below 900 meters. Flowering from February to June, this plant produces purple flowers in large spiny heads up to 6 centimeters in diameter. Growing with tall stems 20 to 300 centimeters high that are glabrous or slightly woolly, it has a distinctive branching habit. Its basal leaves reach 15 to 60 centimeters long with winged petioles, while cauline leaves have spiny, clasping bases that coil around the stem. The fruit is 6 to 8 millimeters long, tan to brown, and often marked with black spots.

Habitat: Invasive. Roadsides, pastures, disturbed areas

Bloom period: Feb-Jun

Elevation: < 900 m

Bioregions: NCo, NCoR, CaRF, n&ampc SNF, 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.