Branchlets terete, glabrous; tendrils 5-8-branched, young apex enlarged as somewhat globose adhesive disks. Leaves of two types, simple and small on long branches, usually 3-foliolate on short branches; simple leaves: petiole 5-20 cm, glabrous; blade oval, 3-7 cm long, 2-5 cm wide, basal veins 3-5, lateral veins 2 or 3 pairs, base cordate or slightly so, margin 4- or 5-toothed on each side, apex acute or acuminate; 3-foliolate leaves: central petiolule short, 3-10 mm, glabrous; lateral leaflets sessile, ovate-elliptic, 5.5-19 cm long, 3-7.5 cm wide, base conspicuously asymmetric and subrounded, outer margin 5-8-toothed, apex acuminate; central leaflet oblong, 6-21 cm long, 3-8 cm wide, with 5 or 6 pairs of lateral veins, veinlets slightly raised, base cuneate, margin 3-8-toothed on each side, apex acuminate. Polychasium pseudoterminal, with inconspicuous rachis, 3-12 cm; peduncles absent to 3 cm, glabrous; bracteoles ovate, 1.5-2 × 1-2 mm, apex acute, glabrous. Pedicel 1-2 mm, glabrous. Buds 2-3 mm, apex rounded. Calyx undulate or subentire. Petals 5, obovate-elliptic, 1.5-2.7 mm, glabrous. Filaments 0.4-0.9 mm; anthers yellow, elliptic or ovoid-elliptic, 0.7-1.5 mm. Disk inconspicuous. Ovary globose; style short; stigma inconspicuously enlarged. Berry black-purple at maturity, 8-10 mm in diameter, 1-4-seeded. Seeds obovoid, base acute, apex rounded.