Description from Flora of China
Herbs, perennial, climbing, scandent, or prostrate. Roots usually tuberous. Stems herbaceous, scabrous. Tendrils simple or 2-fid. Leaves mostly simple, vary rarely pedately 3-7-foliolate; leaf blade cordate, margin dentate. Plants dioecious. Male flowers in cymes-racemes or rarely solitary; calyx tube broadly campanulate or cupular; segments 5, linear, lanceolate, ovate-lanceolate, or oblong, 1-3-veined; corolla yellow, campanulate, 5-partite; segments oblong, broadly ovate, or obovate, usually 5-7-veined, entire; stamens 5, inserted on calyx tube, free, often 4 in pairs, other 1 free; filaments short; anthers oblong or ovoid, all 1-celled; anther cell erect; rudimentary ovary glandlike. Female flowers solitary or 2- or 3-fascicled on a short peduncle; calyx and corolla as in male flowers; ovary ovoid, oblong, or fusiform, smooth or verrucose; ovules numerous, horizontal; style 3-fid; stigmas 3, 2-lobed, reniform. Fruit fleshy, indehiscent, smooth or verrucose, many ribbed or not ribbed. Seeds numerous, horizontal.
Twenty-three species: Bhutan, China, India, Indonesia, Japan (introduced), Korea, Laos, Myanmar, Nepal, Thailand, Vietnam; 23 species (19 endemic) in China.
(Authors: Lu Anmin (路安民 Lu An-ming); Charles Jeffrey)