||China (Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang), India, Japan, Laos, Nepal, Philippines, Thailand, Vietnam
||2n = 38
Branchlets terete, with longitudinal ridges, with sparse arachnoid tomentum when young, becoming glabrescent; tendrils bifurcate. Leaves simple; stipules caducous; petiole 1.5-7 cm, with sparse arachnoid tomentum or subglabrate; leaf blade ovate, triangular-ovate, oval, or ovate-elliptic, 2.5-12 × 2.3-10 cm, abaxially with sparse arachnoid tomentum when young, eventually glabrescent, basal veins 5, lateral veins 4 or 5 pairs, veinlets inconspicuous, base slightly subcordate or subtruncate, rarely cordate, often asymmetrical, leaves with cordate bases with obtusely angled notch, margin with 5-12 slightly irregular teeth on each side, apex acute or acuminate. Panicle leaf-opposed, loose, 4-12 cm, basal branches well developed, or short and slender; peduncle 2-5 cm, with sparse arachnoid tomentum or nearly glabrescent. Pedicel 1.1-2.5 mm, glabrous. Buds obovoid, 2-3 mm, apex rounded and subtruncate. Calyx glabrous, undulately lobed. Filaments filiform, 0.7-1.3 mm; anthers yellow, oval, 0.4-0.6 mm. Pistil abortive in male flowers; ovary oval; style short. Berry globose, 8-10 mm in diam. Seeds obovoid, apex subrounded, chalazal knot elliptic, raphe slightly raised and surface smooth, ventral holes furrowed upward 1/4 from base.