Description from Flora of China
Herbs, climbing, annual or perennial. Tendrils simple or 2- to many fid. Leaves undivided, divided, or pedately 5-7-foliolate. Plants monoecious. Male flowers in raceme or panicle; calyx tube cup-shaped or cupular; segments 5, subulate, sometimes almost obsolete; corolla rotate, 5-partite; segments broadly ovate-oblong, usually acute; stamen 1; filament very short; anther horizontal, 1-celled, circular. Female flowers solitary, binary, or 3-fasciculate; calyx and corolla as in male flowers; ovary ovoid, 1-locular; style very short; stigma large, orbicular. Fruit ovoid or reniform, ± fleshy, setose or setiform, rarely glabrous. Seeds few to numerous, compressed, angled, 2-lobed at apex and base.
About 20 species: tropical America; one species (introduced) in China.
(Authors: Lu Anmin (路安民 Lu An-ming); Charles Jeffrey)