Branchlets terete, nearly glabrous or sparsely pilose; tendrils 5-9-branched, young apex expanded and ball-shaped. Leaves simple, usually 3-lobed on short branches, or small and unlobed on long branches; petiole 4-12 cm, glabrous or sparsely pubescent; blade obovoid, 4.5-17 × 4-16 cm, abaxially glabrous or midvein abaxially sparsely pubescent, basal veins 5, lateral veins 3-5 pairs on each side, veinlets slightly raised abaxially, inconspicuous adaxially, base cordate, margin with rough teeth on each side, apex acute. Polychasium 2.5-12.5 cm; rachis inconspicuous; peduncles 1-3.5 cm, nearly glabrous. Pedicel 2-3 mm, glabrous. Buds obovoid-elliptic, 2-3 mm, apex rounded. Calyx entire or undulate. Petals elliptic, 1.8-2.7 mm, glabrous. Filaments 1.5-2.4 mm; anthers ovoid-elliptic, 0.7-1.4 mm. Disk inconspicuous. Ovary oval; style conspicuous, base thick; stigma not enlarged. Berry 1-1.5 cm in diam., 1-3-seeded. Seeds obovoid, base with a sharp, short rostrum, apex rounded. Fl. May-Aug, fr. Sep-Oct. 2n = 40.