Annual, up to 25 cm tall, erect, branched usually from below, glabrous, glaucous. Basal leaves not rosette forming, ovate-oblong, 1-3 cm long, 0.5-1 cm broad, entire or subentire, shortly stalked; upper leaves oblong-ovate, 1-3.5 cm long, 0.5-2 cm broad, cordate, amplexicaul, apex obtuse or rounded. Racemes 25-50-flowered, up to 15 cm long in fruit. Flowers c. 2 mm across, white; pedicels up to 5 mm (rarely more) long in fruit, sub-spreading or ascending. Sepals c. 1.2 mm long, 0.5 mm broad. Petals c. 2 (-3) mm long, 1 mm broad. Stamens 0.8 :1 mm long; anthers c. 0.2 mm. Siliculae obcordate-orbicular, 10-12 mm in diam. (or a little broader), apical notch narrow with a sessile stigma at its base; wing broadest towards the apex; 2-2.5 mm broad, distinctly reticulately veined; septum 1.5-2 mm wide; seeds usually 6 in each locule, c. 1.5 nun long, reddish-brown.