Annuals; hispid basally, sub-glabrate or glabrous distally. Stems erect or ascending, usually branched distally, 1-8 dm, sparsely hispid basally. Basal leaves rosulate; petiole 0.3-3 cm; blade oblanceolate, 0.7-9 cm × 4-25 mm, margins coarsely dentate-sinuate. Cauline leaves (median) sessile; blade lanceolate to narrowly ovate, 0.5-11 cm × 2-45 mm, (smaller distally, base amplexicaul), margins entire or denticulate. Racemes (densely flowered), with a terminal cluster of sterile flowers. Fruiting pedicels ascending to divaricate, 3-18(-27) mm, pubescent or glabrous. Flowers: sepals erect to ascending, (dark purple in bud, becoming greenish or creamy white and purplish or brown distally), ovate to narrowly lanceolate, 6-17 × 2.5-3.5 mm (subequal, keeled, usually glabrous, rarely pubescent, trichomes simple); petals white (with dark purple veins), 8-20 mm, blade 4-8 × 1.5-2 mm, crisped, claw oblanceolate, 4-11 × 2-3 mm; filaments in 3 unequal pairs, (median pairs often connate), abaxial pair 3.5-11 mm, lateral pair 2-7 mm, adaxial pair 5-12 mm; anthers oblong to linear-oblong, unequal, 1.5-4 mm, (adaxial pair smaller). Fruits erect or ascending (often straight), terete or slightly latiseptate, 5-12 cm × 2.5-3.5 mm; valves each with prominent midvein basally; ovules 52-72 per ovary; style 0-4 mm; stigma strongly 2-lobed (lobes 1-4 mm, opposite valves). Seeds 2-3.5 × 1.7-2.2 mm. 2n = 28.

Flowering (Feb-)Mar-May. Grassland, chaparral, scrub; of conservation concern; 100-1100 m; Calif.