Annuals; glabrous or pubescent. Stems unbranched or branched basally and distally, 1.5-7(-10) dm, (often white-hispid proximally and trichomes simple, glabrous distally). Basal leaves: petiole 1-4(-6) cm; blade lanceolate (in outline), lyrate to sinuate-pinnatifid, or runcinate-pinnatisect, (1-)3-15(-19) cm, lateral lobes oblong or lanceolate, (smaller than terminal lobe). Cauline leaves: (distalmost) blade lanceolate or sublinear. Fruiting pedicels divaricate, straight, 1.5-2.5(-3) cm. Flowers: sepals ascending to spreading, 3-4 × 1-1.5 mm; petals (8-)10-13 × 4.5-6 mm, claw minute or absent; filaments 3.5-6 mm; anthers 1-1.3 mm. Fruits oblong to subglobose, subquadrangular, with 4 irregularly dentate wings, 4-loculed, (0.8-)0.9-1.3(-1.4) cm × 5-6.5 mm; style 3.5-5(-6) mm. Seeds 3 or 4 per fruit, 2-3.5 mm. 2n = 14.
Flowering Apr-Jun. Roadsides, fields, pastures, disturbed areas, waste places; introduced; Pa., Va.; s Europe; sw Asia; n Africa.