Annual or biennial, 30-100 cm tall, erect, branched, ± hairy with simple hairs. Lower leaves long-stalked; stalk up to 8 cm long; blade broadly cordate, acuminate, coarsely toothed, up to 16 cm long, 9 cm broad; upper leaves shortly stalked to subsessile; all leaves roughly hairy with simple appressed hairs. Racemes 10-20-flowered, lax, ebracteate, up to 20 cm long in fruit. Flowers c. 3 cm across, purple, violet, pink or white; pedicels up to 15 mm long in fruit, spreading. Sepals 8-12 mm long, 2.5-3 mm broad. Petals 25-30 mm long, 8-10 mm broad, obovate, long clawed, conspicuously veined. Stamens 8-10: 10-15 mm long; anthers 2.5-3 mm long. Siliculae elliptic-oblong to almost orbicular, rounded at both ends, 30-45 mm long, 20-25 mm borad; septum broad, membranous, not veined ; seeds few, 5-8 mm in diam., winged uniformly (wing c. 1 mm broad).