Herbs, climbing, with a multi-tuberous base. Stems slender. Leaves cordate, 5-lobed, glandular at base. Tendrils 2-fid. Plants dioecious; male flowers in panicle, female flowers often in panicle, sometimes solitary or fascicled. Male flowers: calyx rotate, 5-partite; segments linear-lanceolate; corolla rotate, 5-partite; segments narrowly lanceolate, caudate-acuminate; stamens 5; filaments free or connate at base in pairs; anthers subovoid, 1-celled; connective papillose on back. Female flowers: calyx and corolla as in male flowers; ovary subglobose, verrucose, 3-locular; style short; stigmas 3, 2-lobed; ovules 2 in each locule, pendulous. Fruit narrowly ovoid, conical at apex, with or without spines, circumscissile-dehiscent above middle. Seeds 4-6, subovate, with membranous wing at apex.