Annual with lax rosette. Stems erect or ascending, glabrous, to 1.5 m tall, sometimes becoming subwoody below. Lower lvs petiolate, lyrate-pinnatifid with large terminal and 1-3 pairs of lateral lobes, bright green, bristly, 15-25-(30) × 5-10 cm; margins sinuate, toothed. Upper lvs becoming amplexicaul, glaucous, not lobed, sessile, glabrous, narrowly triangular, entire, 2-10 × 1-2 cm. Racemes to 40 cm long; open fls overtopping buds. Sepals narrow-oblong, (4)-5-7 × 1-1.5 mm. Petals bright yellow, 6-10 × 3-4 mm. Lateral stamens spreading. Silique terete, glabrous, linear-lanceolate, slightly constricted between seeds, (30)-40-60 × 2-5 mm; gynophore 0; valves with prominent median and weaker lateral veins; beak tapering, seedless, 6-10 mm long. Seeds reddish brown, 1-1.5 mm diam.