Perennial. Stems erect, glabrous, ridged or grooved, 10-50 cm tall; branches sometimes sparsely puberulent below. Lvs glabrous. Basal and lower stem lvs withering or falling at fruiting, (3)-5-12-(25) × 1-3-(4) cm, deeply pinnatisect with narrow acute curved teeth on distal edges of pinnae. Upper lvs becoming linear, 3-fid at apex or entire, 5-20-(40) × 1-2-(3) mm; marginal denticles present especially near cuneate lf base. Racemes (3)-5-7-(10) cm long; rachis glabrous; pedicels erecto-patent to patent, (2)-3-4 mm long at fruiting, with hairs in 1 row. Sepals hairy or glabrous, green or purple, 0.7-1 × 0.2-0.3 mm; petals white, minute or 0. Stamens 2. Silicles ovate to rhomboid, 2.4-2.7-(3) × 1.8-2 mm; stigma almost sessile, included in shallow notch; valves green or purple, glabrous. Seed ovoid, brown, not winged, c. 1.4 mm long.