Rootstock of ovoid-globose tubers borne on stalks from a rhizome. Stem twining to left, with T-shaped hairs. Bulblets absent. Leaves alternate, simple; leaf blade ± ovate, with T-shaped hairs, margin entire. Male inflorescence usually solitary, a spike or raceme. Flowers usually solitary, sometimes in dense umbellules; perianth saucer-shaped; stamens 6. Capsule reflexed at maturity, longer than wide. Seeds inserted at middle of capsule, winged all round.

One species: India, Malaysia, Papua New Guinea, Thailand; long cultivated in tropical Asia; one species (introduced) in China.