Description from Flora of China
Woody climbers, evergreen. Young branches striate; old branches waxy; bud scales triangular, thick, pilosulose. Petiole 8-10 mm; leaf blade abaxially light green, adaxially dark green and shiny, black when dried, narrowly oblong or narrowly obovate-elliptic, rarely ovate, 6-10 × 2-4 cm, thinly leathery, both surfaces glabrous, lateral veins 3-5 pairs, slender, ascending, anastomosing near margins, reticulate veins sparse, base broadly cuneate or cuneate, apex caudate-acuminate. Cymes usually 3(-5)-flowered; peduncles 3-4 cm. Pedicel 4-8 mm. Sepals 5, triangular-ovate, ca. 1.5 mm, ciliate. Petals 5, light green, ovate, obovate, or oblong-ovate, 5-6 × 3.5-4 mm, 9-veined, apex rounded. Stamens 5, 3-3.5 mm; filaments flattened; anthers introrse. Disk shallowly cup-shaped. Ovary glabrous. Schizocarp blue when mature, obovoid, 6-7 mm; endocarp with midrib, with foveolate. Fl. May, fr. Aug-Sep.
● Dense forests, valleys, hillsides, streamsides; below 900 m. N and W Guangdong, N Guangxi.