Annual herb. Stem erect, hairy at base, to 1 m tall. Rosette and lower stem lvs sparsely hispid especially below, pinnatifid, rarely almost 2-pinnatifid, 5-15-(30) × 1.5-7-(10) cm, with 5-9-(12) pairs of toothed triangular lobes. Upper stem lvs glabrous, smaller, pinnatifid with linear-filiform segments. Racemes often flexuous, ebracteate, suberect or spreading, glabrous, 10-30 cm long. Pedicels c. 5 mm long at flowering, elongating to up to c. 10 mm long at fruiting, glabrous. Sepals glabrous, 3-4 mm long, the outer pair with short horn at apex (most conspicuous in bud). Petals yellow, 6-8 mm long. Anthers at least 1 mm long; filaments = or slightly > sepals. Silique glabrous, spreading, linear-cylindric, (40)-70-110 × 1-1.5 mm; style 0.5-1 mm long. Seeds ovoid to oblong, brown, c. 0.8 mm long.