Biennial, tall and robust, 30-60 (-90) cm long, erect, branched, appressedly canescent with 2 (rarely 3-4)-partite hairs. Basal leaves ± rosulate, oblanceolate, 50-80 mm long, 5-10 mm broad, stalked, entire or shortly toothed, acute. Race¬mes 30-50-flowered, up to 30 cm long in fruit. Flowers 10-12 mm across, yellow; pedicels up to 5 mm long in fruit, thickened, subspreading or ascending. Sepals 6-9 mm long. Petals 12-16 mm long, 3-4 mm broad. Stamens c. 7: 9 mm long; anthers c. 2 mm long. Siliquae subcylindrical, terete, 40-55 mm long, c. 1.2 mm broad, straight, often horizontally spreading, appressedly hairy; valves with a prominent mid-rib; stigma capitate, bilobed, subsessile; seeds c. 1.5 mm long, brown.