Perennials or subshrubs; (evergreen, with sterile shoots); glabrous. Stems decumbent, branched basally and distally, (0.5-)1-2.5 dm. Basal leaves (of sterile shoots) sessile; blade linear-oblanceolate, 1-3(-5) cm × 2-5 mm. Cauline leaves (of flowering shoots) similar to basal, blade smaller, margins entire. Racemes slightly elongated in fruit. Fruiting pedicels divaricate-ascending, 4-11 mm. Flowers: sepals oblong or ovate, 2-4 mm; petals white or sometimes pink, abaxial pair 5-13 × 2-7 mm, adaxial pair 3-6 × 1-3 mm. Fruits suborbicular to broadly ovate, 6-8 × 5-6 mm, apically notched; valves extending into subacute wing; style 1-3 mm, exserted beyond apical notch. Seeds narrowly winged, 2-3 mm. 2n = 22. Flowering Apr-Jul. Escape from cultivation, abandoned gardens; introduced; Calif., Mich., N.Y.; s Europe; introduced also in South America.