Description from Flora of China
Vitis assamica M. A. Lawson in J. D. Hooker, Fl. Brit. India 1: 648. 1875.
Lianas, woody. Branchlets terete, with longitudinal ridges, with sparse, appressed and versatile hairs, or nearly glabrous; tendrils bifurcate. Leaves simple; stipules oval, ca. 3 × 2-2.5 mm, herbaceous, nearly glabrous, apex obtuse; petiole 2-9 cm, with sparse, appressed and versatile hairs or glabrescent; leaf blade broadly cordate or cordate-oval, 5-17 × 4-14 cm, abaxially veins with sparse appressed and versatile hairs or glabrescent, basal veins 5, lateral veins 4-6 pairs, veinlets conspicuous abaxially, base cordate, notch rounded or obtuse, margin with 20-44 sharp teeth on each side, apex mucronate or acute. Inflorescence umbelliform, leaf-opposed; peduncle 2-2.5 cm, with sparse, appressed versatile hairs or subglabrate. Pedicel ca. 2.5 mm, with sparse, appressed versatile hairs. Buds oval, 2-3 mm, apex obtuse. Calyx subglabrate, entire or undulate. Petals triangular-oval, 1.5-2 mm, glabrous. Anthers oval. Disk conspicuous, 4-divided. Lower part of ovary adnate to disk; style conical; stigma slightly expanded. Berry purple-black at maturity, 7-10 × 6-7 mm, 1-seeded. Seed surface with sharp and raised ridges, ventral holes short and narrow upward 1/3 from base. Fl. May-Jun, fr. Jul-Oct. 2n = 48.
Forests or shrublands by rivers; 200-1600 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, Xizang, Yunnan [Bhutan, Cambodia, India, Nepal, Thailand, Vietnam].