Plants polygamo-dioecious. Branchlets terete, with conspicuous longitudinal ridges, sparsely lanate when young, becoming glabrescent; tendrils bifurcate, leaf-opposed. Leaves simple; stipules caducous; petiole 3-6 cm, with long villous arachnoid tomentum when young, then falling off and pubescent; leaf blade oval or oblong, 6-13 × 5-11 cm, both surfaces with villous tomentum when young, then becoming sparsely so, abaxially whitish pubescent on lateral veins, basal veins 5, lateral veins 3-5 pairs, veinlets conspicuous abaxially, base deeply cordate to cordate, notch rounded or obtuse, margin 16-25-toothed on each side, teeth sharp and slightly irregular, apex acute or acuminate, rarely rounded. Panicle leaf-opposed, loose, 5-11 cm, basal branches well developed, sometimes with a tendril below basal branch, with sparse arachnoid tomentum when young, then falling off. Pedicel 1-1.5 mm, glabrous. Buds obovoid, 2-2.5 mm, apex rounded. Calyx glabrous, teeth inconspicuous. Filaments filiform, ca. 1 mm; anthers yellow, elliptic, ca. 0.2 × 0.1 mm. Ovary conical; style short. Berry purple-black at maturity, globose, 8-10 mm in diam. Seeds obovoid, apex retuse, chalazal knot elliptic, ventral mid-raphe slightly raised.