Description from Flora of China
Vines evergreen, twining, 0.5-5 m, glabrous. Branchlets terete. Leaves opposite, simple; petiole 4-12 mm, articulate near base; leaf blade linear to narrowly elliptic or narrowly ovate, 5-12.5 × 0.7-3.3 cm, leathery, 3-veined, base cuneate or rounded, apex acuminate to caudate, rarely obtuse or acute. Flowers usually solitary, terminal or axillary, or in 1-8-flowered cymes; bractlets linear, 2-5 mm. Pedicel 0.7-2.3 cm. Calyx tube 2-3 mm; lobes 4-12, linear, 2-3(-4) mm. Corolla white, salverform; tube 1.6-2.4 cm; lobes 8-12, lanceolate or linear-lanceolate, 1.5-2 cm, spreading. Berry black and shiny, oblong-ovoid, 0.8-2.2 cm × 4-11 mm. Fl. May, fr. Aug-Dec. 2n = 26*, 52*.
Valleys, thickets, rocky slopes; below 1200 m. Guangxi, Hainan, Xizang, Yunnan [India, Myanmar]