Herb biennial. Stems erect, branched, terete, longitudinally ridged, 50–140 cm tall, red or green. Leaves alternate, 3-foliolate; stipules lanceolate, 1–2 pairs on petiole base, 6–8.4 mm long, green, sometimes red at apex; petioles 6.2–10.8 mm long, hair; leaflets oblong to oblanceolate, 2–3 × 0.4–0.5 cm, green, margin needle-shaped teeth, 9–12 pairs on a side, longest apex teeth. Inflorescence raceme, 2.4–5 cm long, 28–43 flowers; peduncle and pedicel hair. Flowers calyx 1.8–2.2 mm long, hair, lobes 5, lanceolate; petals 3.4–4.3 mm long, standard slightly longer than wings and keel, yellow; stamen 10, diadelphous; pistil 1; ovary elliptic, ovule 2. Fruits legume, ovate to globular, 3.3–3.5 × 2–2.4 mm, green or partially pale red, surface minute reticulate nerved or smooth. Seeds 1–2, broadly elliptic to rounded, 1.8–2.4 × 1.6–1.8 mm, dark green or greenish brown.
