Stems annual, 1–2 ft. high, slender, slightly pubescent, and diffuse. Stipules 3–4 lines long, linear, deciduous. Petioles 1/2–1 in. long; leaflets 3, the terminal one roundish or ovate, 1–2 in. long, 1/2–1 in. broad, the lateral ones smaller, sub-papyraceous, both sides green glabrous. Racemes very lax, terminal and axillary, the former often compound. Bracts minute, setaceous, deciduous. Pedicels 3–4 lines long, spreading, very slender, glabrous. Calyx a line deep, deep-cleft, the teeth setaceous. Corolla slightly exceeding the calyx, greenish, variegated with purple. Pod 3/8– 1/2 in. long, a line broad, with 4–6 articulations separated by very narrow spaces, often spirally twisted, the faces minutely pubescent.