Annuals; not scapose. Stems (usually simple, rarely more, from base), unbranched or branched distally, (0.5–)0.7–3(–3.7) dm, pubescent, proximally trichomes simple and stalked, 2-rayed, 0.4–1.3 mm, with 3- or 4-rayed ones, 0.05–0.2 mm, distally trichomes stalked and 2–4-rayed. Basal leaves rosulate; petiole (obscure), margin ciliate, (trichomes simple, to 1.5 mm); blade oblanceolate to obovate, 1–2(–3) cm × 2–7(–10) mm, margins entire or subapically denticulate, surfaces pubescent, abaxially with simple, 0.6–1.3 mm, and stalked, 2–4-rayed trichomes, 0.1–0.8 mm, adaxially with simple and stalked, 2-rayed ones, 0.4–1.2 mm. Cauline leaves 3–10(–17); sessile; blade lanceolate to ovate or oblong, margins entire, surfaces pubescent as basal. Racemes (15–)20–51(–62)-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels horizontal to divaricate-ascending, straight or curved upward, (2–)3–8(–10) mm, pubescent, trichomes simple and stalked, 2–4-rayed. Flowers: (late-season ones petaliferous); sepals oblong, 1.3–2 mm, pubescent, (trichomes simple); petals yellow (sometimes fading white), oblanceolate, 1.5–3 × 0.5–1 mm; anthers ovate, 0.2–0.3 mm. Fruits lanceolate, plane, flattened, 6–9(11) × 1.3–2.3 mm; valves pubescent, trichomes simple, antrorse, 0.1–0.2 mm; ovules 32–60 per ovary; style 0.01–0.1 mm. Seeds ovoid, 0.5–0.7 × 0.4–0.5 mm. 2n = 24.
