Derris monticola - Mountain Derris

Mountain Derris is is a large climber with twigs 3-5 mm in diameter, striped, hairless, warty. Leaves are compound with 9-11 leaflets. Leaf-stalks are about 9.5 cm long, leaflets somewhat leathery; end one narrowly obovate, about 8.5 x 2.7 cm. Lateral ones mostly like end one, elliptic to narrowly obovate, 6-9 x 2.3-2.5 cm. Flowers are borne in leaf-axils, in pseudoracemes 12-17 cm long, carried on flower-cluster-stalk 1.7-2.5 cm long. Flower-stalks are 4-4.5 mm long, silky. Sepal-cup is cup-shaped, 3-3.5 mm high, outside silky, tube about 3 mm high; upper lip with 2 short lobes, 0.3-0.4 x 1.8-2 mm; lateral lobes triangular, 0.5-0.7 x 1-1.5 mm; lower lobe triangular, about 1 x 1.5-2 mm. Flowers are pink or purple. Standard has claw 1.5-2 mm long; blade round or ovate, 10-12 x 8.5-10 mm, tip notched. Wings have claw 2.5-2.8 mm long; blade narrowly obovate, 7.3-7.5 x 2.5-2.7 mm, tip rounded. Keel petals have claw 2.5-2.8 mm long; blade boat-shaped, 7-7.2 x 3.4-3.5 mm, tip rounded. Pods are narrowly elliptic or strap-like, flat, hairless, 7-10 x 1.5-2.5 cm, with a wing along both sutures. Mountain Derris is found in Bangladesh, East Himalaya, Myanmar, Nepal, Thailand, at altitudes of 700-2000 m. Flowering : May-June.