Annual or biennial herb, 20-30(-40) cm tall, erect, sparsely branched or simple, glabrous above and sparsely hairy below. Basal leaves loosely rosulate, cordate to reniform, long-petioled, dentate; lamina usually 10-15 cm long, 2-6 cm broad; cauline leaves often ovate-triangular, dentate, shortly stalked; all leaves thin or submembranous, pale greem. Racemes 15-30-flowered, up to 30 cm long in fruit, lax. Flowers c. 5 mm across, white; pedicels 5-8 mm long in fruit, strong and thickened, spreading. Sepals c. 2.5 mm long. Petals (5-)6-8 mm long, c. 2 mm broad. Stamens c. 2.5: 3.5 mm long; anthers c. 1 mm long. Siliquae (30-) 45-60(-70) mm long, c. 2 (-2.5) mm broad, linear-terete, often straight, suberect or erect; style 1-3 mm long with a depressed stigma; seeds many, c. 3 mm long, 1 mm broad, oblong, dark-brown to almost black, longitudinally striated.