Stems branched basally and distally, (0.5-)0.7-3.6(-4.5) dm. Basal leaves: petiole 1-4.5 cm; blade 3-6 lobes each side, 1.5-4 cm, terminal lobe linear to oblong, 0.3-1.5 cm × 0.5-1.5 mm, margins entire. Cauline leaves similar to basal. Fruiting pedicels 2.5-4 mm. Flowers: sepals 4-5 mm; petals 6.5-8 × 1-2 mm; median filaments 3.5-4 mm; anthers 0.5-0.8 mm. Fruits reflexed; proximal segment broadly ovoid to subglobose, 3-4 × 2.5-3.5 mm; terminal segment cochleariform or ovate, 3-5 × 3-4 mm (margin incurved). Seeds 1.1-1.6 mm diam. 2n = 16. Flowering Apr-May. Deserts; ca. 50 m; introduced; Calif.; sw Europe; sw Asia; n Africa; introduced also in Australia. Carrichtera annua was found as a naturalized weed in southern California in 2007.