Caulanthus flavescens

Yellow California mustard

Family: Brassicaceae · Type: annual · Native

Yellow California mustard is a native annual found in southern North Coast Ranges Interior, Sacramento Valley (Montezuma Hills), southeastern San Francisco Bay Area, and southern Coast Ranges Interior on dry, exposed slopes and open hillsides, often on serpentine soils at elevations of 80 to 750 meters. Flowering from March to May, this plant produces delicate white or cream flowers with subtle pink tones, 7 to 13 millimeters long with wavy margins. Growing with erect stems 70 to 120 centimeters tall, it can be either glabrous or covered in stiff hairs, and may branch out in its upper portions. Its leaves vary from lyre-shaped basal leaves to lance-shaped cauline leaves, with lower leaves 2 to 13.5 centimeters long and petioled, while upper leaves are sessile. The fruit is an ascending to reflexed pod 3.8 to 7.7 centimeters long, containing 44 to 58 small oblong seeds.

Habitat: Dry, exposed slopes, open hillsides, vertic clay, often serpentine

Bloom period: Mar-May

Elevation: 80-750 m

Bioregions: s NCoRI, ScV (Montezuma Hills), se SnFrB, SCoRI.

California counties: Colusa, Alameda, San Benito, Glenn, San Joaquin, Solano, Monterey, Contra Costa, Stanislaus, Lake, Riverside, Santa Clara, Napa, 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.