Cirsium fontinale var. obispoense

Chorro creek bog thistle, San Luis Obispo Fountain Thistle

Family: Asteraceae · Type: perennial · Native

Conservation status: CNPS 1B.2 · Endangered

Chorro creek bog thistle is a rare (CNPS 1B.2) California native perennial found in central San Luis Obispo County in serpentine seeps and streams at elevations below 350 meters. Flowering from April to October, this plant produces purple flowers in nodding heads with distinctive green to dark purple phyllaries that have strongly recurved outer bracts. Growing up to 2 meters tall with green to purple stems, it develops dense cobwebby leaves with longer leaf spines measuring 4 to 7 millimeters. Its leaves are densely covered in velvety hairs, with the undersides especially concealed by soft, web-like textures. The plant's flower heads feature intricate phyllary structures with outer bracts that are strongly curved and up to 20 millimeters long.

Habitat: Serpentine seeps and streams

Bloom period: Apr-Oct

Elevation: < 350 m

Bioregions: c SCoRO (San Luis Obispo Co.).

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