Annual or biennial herb with lax rosette. Stems erect or ascending, becoming subwoody below, glabrous, to 1.5 m tall. Lower lvs petiolate, lyrate-pinnatifid with 1-3 pairs of lateral lobes, glaucous, bristly, especially on veins, often ciliate, 10-30 × 5-15 cm. Upper lvs glaucous, becoming entire, sessile, amplexicaul, glabrous, narrow-triangular, entire or toothed, 2-10 × 1-2 cm. Racemes to 40 cm long; open fls slightly below level of buds. Sepals erecto-patent, (4)-5-7 × 1-2 mm. Petals bright to pale yellow, 10-12 × (4)-5-6 mm. Lateral stamens spreading. Silique terete, glabrous, narrowly oblong, slightly constricted between seeds, (50)-60-80 × 2-5 mm; gynophore 0; valves with pronounced median and weak lateral veins; beak tapering, seedless, 8-15 mm long. Seeds dark brown to blue-black, 1.5-2.5 mm diam.