Annuals or biennials; (fetid); puberulent (trichomes cylind-rical). Stems simple from base, erect ascending, branched (several) distally, (0.5–)1–3.5(–5.5) dm. Basal leaves rosulate; petiole 1–3.2(–5.3) cm; blade (1- or) 2- or 3-pinnatisect (lobes oblong), (1.5–)3–5(–7.2) cm, margins (of lobes) usually entire, rarely dentate. Cauline leaves sessile; blade linear, (0.4–)1–2(–3) cm × 0.5–2.5(–3.5) mm, base cuneate, not auriculate, margins entire. Racemes considerably elongated in fruit; rachis puberulent, trichomes straight, cylindrical. Fruiting pedicels divaricate to horizontal, straight, (terete), (1.5–)2–4(–5) × 0.1–0.15 mm, puberulent. Flowers: sepals oblong, 0.5–0.9(–1) × 0.2–0.4 mm; petals (absent or rudimentary), white, linear, 0.2–0.5 × 0.1 mm, claw absent; stamens 2, median; filaments 0.7–0.8 mm; anthers 0.1–0.2 mm. Fruits elliptic, (1.5–)1.8–2.5(–3) × 1.5–2(–2.3) mm, apically winged, apical notch 0.1–0.2 mm deep; valves thin, smooth, not veined, glabrous; style obsolete or to 0.1 mm, included in apical notch. Seeds oblong to ovate-oblong, 1–1.5 × 0.6–0.8 mm. 2n = 16, 32.
