Liana 3–15 m high with white latex; branches dark brown with large pale brown lenticels; branchlets glabrous or puberulous. Leaves petiolate; blade (narrowly) elliptic, 3–9 cm long, 1–5 cm wide, bluntly acuminate to obtuse at the apex, cuneateor rounded at the base, glabrous on both sides or puberulous beneath; with 11–14 pairs of rather straight secondary veins at an angle of 40–50° with the midrib; petiole 2–5 mm long, glabrous or puberulous. Inflorescence terminal, few- to many-flowered, 2–5 cm long, glabrous or puberulous; peduncle 1–18 mm long; bracts sepal-like; pedicels 5–15 mm long. Flowers with sepals ovate, up to 2.8 mm long, with 1–2 colleters near the edge inside; corolla white or greenish white; tube often partly reddish, throat red; mature bud with a narrowly ovoid head about twice as long as the tube; tube 4–6.5 mm long; lobes twisted in bud, spoon-like with a shallow concave apex, obliquely obovate or elliptic, 9–14.5 mm long, 3–5.5 mm wide, rounded at apex; stamens inserted 2.2–4 mm from the base; style 2–2.2 mm long. Fruit brown, 40–50 cm long, 0.5 cm in diameter; seed up to 15 mm long; coma 3 cm long.