Liana 3–25 m high with white latex; branches dark brown with pale brown lenticels; branchlets glabrous. Leaves petiolate; blade (narrowly) elliptic, 3–9 cm long, 1–4 cm wide, acuminate or caudate at the apex, cuneate or rounded at the base, glabrous, with 4–9 pairs of secondary veins forming an angle of 45–60° with the midrib; petiole 1–5 mm long, glabrous. Inflorescence terminal and often also axillary, few-flowered, glabrous; peduncle 3–16 mm long; pedicels 3–10 mm long. Flowers fragrant; sepals ovate, 1.2–2.2 mm long, 0.8–1.4 mm wide, obtuse, glabrous, with one colleter near the edge; corolla white, tube often partly pink outside; mature bud with an ovoid head about as long as the tube; tube 5–9 mm long, widest at the insertion of the stamens; lobes obliquely oblong or obliquely ovate, 4.5–12 mm long, 2.5–8 mm wide, rounded, spreading or recurved; stamens with apex 1.2 mm below to 1 mm above the mouth of the corolla tube, inserted at 2–5 mm from the base; anthers 2.8–4.5 mm long; style 2.2–4 mm long; pistil head 0.5–1 mm long, stigmoid apex minute; ovules ± 100 in each carpel. Fruit brown, 15–40 cm long, 0.5–1 cm wide, glabrous; seed 15–25 mm long; coma 2.5–3.5 cm long.