Annuals; sparsely to densely hirsute. Stems erect, unbranched or branched distally (or, rarely, basally), 3.5-15 dm, at least sparsely hirsute basally. Basal leaves soon withered. Cauline leaves petiolate (median 0.4-3 cm); blade lanceolate to oblong, 1.5-9.5 cm × 3-30 mm (smaller distally), margins denticulate to subentire (proximal blade margins dentate). Racemes without a terminal cluster of sterile flowers, (considerably elongated in fruit). Fruiting pedicels ascending to strongly reflexed (slender or thickened), 3-10 mm. Flowers: sepals spreading, oblong, 3.5-5.5 × 1-1.7 mm; petals (spreading), white to lavender, 4-8 × 2-4 mm, not channeled or crisped, claw undifferentiated from blade; filaments (spreading), subequal, 3.5-5 mm; anthers narrowly oblong, equal, 1.5-2 mm, (coiled after dehiscence). Fruits erect or reflexed, (straight), terete, 3-6.7 cm × 1.2-2 mm; valves each with prominent midvein, (usually glabrous, rarely sparsely pubescent); ovules 40-54 per ovary; style (subconical or cylindrical), 1-4 mm; stigma subentire. Seeds (brown), 1.4-1.8 × 1-1.3 mm. 2n = 28.

Flowering Mar-May. Grassy slopes, open flats, roadsides, fields, hillsides; 300-1700 m; Calif.

Caulanthus anceps is distributed in Kern, Monterey, San Benito, San Luis Obispo, Santa Barbara, and Ventura counties.