- jack bean, horse bean (Leguminosae), annual or short-lived perennial climber with a deep root system, bushy, twining or prostrate, up to 2 - 3 m long. Stems become somewhat woody with age, branching at lower nodes. Leaves alternate, trifoliate, petiole 11 - 17 cm, acute or rounded and mucronate at top sparsely covered with short hairs on both surfaces. Flowers mauve to purple or sometimes white, borne on an axillary raceme. Pod oblongoid, laterally compressed, 15-35 cm x 3-3.5 cm containing 8-20 seeds, each valve with a sutural rib and an additional rib just below it. Seed oblongoid, laterally compressed, about 21x15 mm x 10 mm. Ivory or white, the hilum brown, 6-9 mm long. Used as a forage for ruminants and is grown extensively as a cover crop or green manure. Young seeds and pods may be used in human nutrition as a vegetable, but only when cooked. Soaked and roasted ripe seeds are eaten as a delicacy in Indonesia. Sold as a snack in bags in Bali.