Annuals; not scapose. Stems usually branched distally, (0.3-)0.7-3(-3.6) dm, pubescent throughout, trichomes short-stalked to subsessile, cruciform, 0.1-0.5 mm. Basal leaves not rosulate; petiolate; petiole (to 1 cm), ciliate throughout; blade obovate to spatulate or ovate to suborbicular, 0.6-2.5 cm × 3-10 mm, margins usually entire, rarely toothed, surfaces pubescent with stalked, cruciform trichomes, 0.1-0.5 mm. Cauline leaves (5-)8-20(-25); sessile; blade oblong to lanceolate, margins entire, (not ciliate), surfaces pubescent as basal. Racemes 7-46-flowered, ebracteate, elongated in fruit, (lateral racemes from axils of distalmost leaves subumbellate); rachis not flexuous, pubescent as stem. Fruiting pedicels horizontal to divaricate-ascending, straight, 2-5 mm, pubescent, trichomes subsessile, 4-rayed. Flowers: (late ones cleistogamous, apetalous); sepals oblong, 0.6-1.2 mm, pubescent; petals white, spatulate, 1.3-2.5 × 0.5-1 mm; anthers ovate, 0.1-0.2(-0.05 in cleistogamous flowers) mm. Fruits linear-ellipsoid to ellipsoid, plane, flattened, (3-)4-6 × 0.8-1.1 mm; valves pubescent, trichomes subsessile, (2-)4-rayed, 0.03-0.12 mm; ovules 4-6(-8) per ovary; style 0.07-0.13 mm. Seeds ovoid, 0.9-1.1 × 0.5-0.6 mm. Flowering Mar-May. Open knolls, rocky roadsides, rock outcrops, igneous glades, woods, alluvial areas near streams; 100-400 m; Ark., Ga., Mo., Okla., S.C.