Astragalus rattanii var. jepsonianus

Jepson's milkvetch

Family: Fabaceae · Type: annual · Native

Conservation status: CNPS 1B.2

Jepson's milkvetch is a rare (CNPS 1B.2) California native annual found in southern North Coast Ranges Interior and central eastern South Coast Ranges Interior, specifically at the northern edge of the New Idria serpentine mass, in grasslands and woodland openings at elevations of 150 to 700 meters. Flowering from April to June, this plant produces white flowers with a distinctive purple-tipped banner, clustered in small groups of 4 to 9 blossoms. Growing as a delicate annual with slender stems, it develops low to the ground in serpentine and vertic clay environments. Its compound leaves feature 7 to 9 leaflets, creating a fine, intricate foliage pattern typical of milkvetches. The plant's adaptation to serpentine soils and its subtle flower coloration make it a unique component of California's grassland ecosystems.

Habitat: Grasslands, grassy openings in woodland and chaparral, vertic clay, often serpentine

Bloom period: Apr-Jun

Elevation: 150-700 m

Bioregions: s NCoRI, ce SCoRI (n edge of New Idria serpentine mass).

California counties: Lake, Colusa, Napa, Glenn, Tehama, San Benito, San Bernardino

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