Micropus amphibolus

Mount diablo cottonseed, Mount Diablo Cottonseed

Family: Asteraceae · Type: annual · Native

Conservation status: CNPS 3.2

Mount diablo cottonseed is a California native annual found in southern North Coast Ranges, western North Coast Ranges, northern Sierra Nevada Foothills, northern Central Coast, San Francisco Bay Area, and southern South Coast Ranges in openings on slopes, ridges, and shallow soils at elevations of 40 to 900 meters. Flowering from March to June, this plant produces white flowers in small spherical heads approximately 3.5 to 5 millimeters in diameter. Growing with compact stems 2 to 20 centimeters tall, the plant forms low, delicate clusters across rocky terrain. Its distinctive paleae (bracts) feature helmet-like shapes with thick, cartilaginous midveins and prominent, flat wings that give the flower heads a unique architectural quality. The tiny fruits are 1 to 1.5 millimeters long with 1 to 5 short bristles.

Habitat: Openings on slopes, ridges, shallow soils, sedimentary or volcanic rocks

Bloom period: Mar-Jun

Elevation: 40-900 m

Bioregions: s NCoRO, w NCoRI, n SNF, n CCo, SnFrB, s SCoRO.

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