Annuals or biennials. Stems unbranched proximally, branched distally, (3-)4-8(-10) dm. Basal leaves: petiole 1-4 (-6) cm; blade lanceolate to oblong or ovate, (2-)4-8 (-10) cm × (10-)15-25(-40) mm, base cuneate to obtuse, margins dentate. Cauline leaves (distal) sessile; blade usually ovate to narrowly oblong, rarely lanceolate, base obtuse to truncate, margins entire, sometimes repand. Fruiting pedicels divaricate, (8-)10-16(-20) mm. Flowers: sepals 3.5-5 × 1-1.5 mm, pubescent abaxially; petals white or lavender, (7-)8-10(-12) × 4-6(-7) mm, attenuate to claw, claw 2-3 mm, not expanded basally; filaments lavender or white, 3-4 mm; anthers 1-1.5 mm. Fruits: each valve suborbicular or orbicular, (7-) 8-10 × (6-)7-10 mm, base rounded, apex truncate, with or without narrow margin beyond indurated part surrounding seeds, glabrous or pubescent; style (0.3-)0.6-1(-1.2) mm. Seeds suborbicular-ovoid, 3-4 × 2.5-3 mm. 2n = 18.

Flowering Apr-Sep. Sandy hills and plains, prairies, sand dunes; 100-800 m; Kans., N.Mex., Okla., Tex.