Deciduous, ± glabrous climber up to 12 m high, usually dioecious or gynodioecious. Twigs green; the outermost scales of the winter buds often transformed into sharp spines 1-2 mm long. Branches terete, greyish brown. Lvs suborbicular, obovate or elliptic, obtuse to acuminate at apex, crenate, (3)-5-10 cm long. Petiole (0.5)-1-2 cm long. Cymes 1-many-flowered, shortly pedunculate, axillary. Fls c. 4-10 mm diam. Petals pale green, narrowly oblong, separated, often reduced in ♀. Capsule globose, yellow to yellow-orange, 6-8 mm diam., exposing the scarlet aril after opening.