Astragalus breweri

Common Names

Brewer's Milkvetch, Brewer's Milk-Vetch

Summary

Brewer's milkvetch is an annual herb native to northern California, forming a small plant with stems a few centimeters long and leaves with widely spaced leaflets and notched tips. It grows in open habitats on serpentine soils, often in the North Coast Ranges and near the north edge of the San Francisco Bay Area. An inflorescence on a rough-haired peduncle bears up to ten pealike flowers, each about 1 cm long, white, yellow, or pale lavender (sometimes with light purple streaks); fruit is an oval legume pod up to 1 cm long containing 2–6 seeds.

Blooms occur from April to June; distribution includes Colusa, Lake, Mendocino, Marin, Napa, Sonoma, and Yolo Counties; habitat includes grassy flats, spring-moist meadows, open chaparral slopes, and valley foothill grasslands below 2000 ft (90–730 m). Endemic to California, conservation status is Vulnerable, and the species is associated with serpentine ultramafic soils.

Lifecycle

Annual

Height

1.5-12 inches

Soil Type

Serpentine (ultramafic) soils, volcanic-derived soils can support populations

Soil Drainage

Well-drained

Bloom Color

White, Yellow, or Pale Lavender (sometimes with light purple streaks)

Bloom Time

Spring

Foliage Color

Green; sometimes cinereous (gray) when young.

Leaf Lifecycle

Deciduous

Growth Rate

Annual

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds

Attracts Wildlife

Bees, true bugs, wasps