Plants climbing. Branchlets and inflorescences sparsely puberulent when young, glabrescent. Branchlets terete, brown, lenticellate. Petiole black, 1-3.5 cm, glabrous; leaf blade lanceolate, elliptic, ovate, or rarely obovate, 10-16 (4-)5-8 cm, abaxially brown when dry, midvein elevated, reticulate veins slightly evident, adaxially black and shiny, base rounded to cordate and oblique, apex abruptly acuminate to acute. Inflorescences spreading, 7-10 X (9-)20-30 cm; branches 5 or 6 pairs, puberulent; bracts lanceolate, 3-6 mm. Flowers subsessile, 4-5 mm. Calyx cup-shaped, ca. 1.5 mm, truncate to slightly 2-lipped; lips slightly 2-dentate, puberulent. Corolla grayish yellow, ca. 3 mm; tube ca. 2 mm, villous in throat, outside glabrous; lobes 4, subequal, apex obtuse to rounded. Stamens as long as style, slightly exserted. Ovary glabrous. Fruit blue-black, obovate, 7-8 X 4-6 mm, tuberculate. Fl. and fr. May-Jul.

Mixed forests; 500 m. Yunnan (Mengla Xian) [Bangladesh, Bhutan, India, Myanmar, Vietnam].