Robust woody liane with milky latex. Bark rough, cracking in square pieces; branches smooth, covered with dot-like lenticels. Leaves elliptic to slightly obovate, 4.5-7.5 cm long, thinly leathery, hairless, with 8-11 paired lateral veins. Flowers in lax inflorescences, creamy-white, tinged maroon on the outside of the corolla. Fruit in thin paired follicles, up to 20 cm long.