Annuals, 15-60 cm. Stems unbranched or sparsely branched; glandular-pubescent. Leaves: stipules absent; petiole (0.6-)1.5-4.5 cm; leaflets 3 proximally, 1 distally, blade linear to elliptic, 0.5-3 × 0.1-0.7 cm, margins entire, apex acute to obtuse, surfaces stipitate-glandular throughout (sparingly hairy abaxially). Racemes 1-3 cm (6-15 cm in fruit); bracts mostly unifoliate, sometimes proximalmost trifoliate, 2-15 mm. Pedicels 7-15 mm. Flowers: sepals greenish with purplish margin, deltate, 0.6-2 × 0.8-1.2 mm, margins denticulate, glabrous; petals whitish or yellow, sometimes red-striped, oblong to ovate, 3-4 × 1.5-2 mm; stamens reddish, 5-6 mm; anthers 0.6-0.9 mm; gynophore (1-)3-5 mm in fruit (subtended by clavate, purple-black gland adaxially); ovary 3-6 mm; style 0.2-0.4 mm. Capsules 25-35 × 1.5-2 mm. Seeds (4-)10-20, reddish brown or mottled black and brown, ovoid-spheroidal, 1.2-1.5(-1.8), not arillate, (finely papillose).

Flowering summer. Railroad yards, ore piles (chrome, vanadium), roadsides; 100-200 m; introduced; Ky., Md., Ohio, Pa.; se Europe; sw Asia.