Woody climbers, 2-3 m, deciduous. Branchlets of current year yellowish green, striate; second-year branches brown, glabrous. Bud scales ovoid, glabrous, ciliate. Petiole 2-10 mm; leaf blade oblong-ovate, 3-13 × 1.5-3.5 cm, papery, both surfaces glabrous, lateral veins 3-5 pairs, ascending, anastomosing near margin, reticulate veins sparse, base rounded or broadly cuneate, apex acute or acuminate. Cyme or panicle 1-3(-20)-flowered, 4-5 cm; peduncle 2-3 cm. Pedicel 8-15 mm. Sepals 5, triangular-ovate, ca. 0.5 mm. Petals 5, light green or greenish purple to brownish chocolate colored, oblong or broadly obovate, 4-5 mm, 7-9-veined. Stamens 5, 3-5 mm; filaments flattened; anthers ovoid, introrse. Disk swollen, cylindric, margin undulate. Ovary glabrous; style ca. 4 mm. Schizocarp obovoid or suborbicular, ca. 6 × 7 mm, glabrous; endocarp with midrib narrowly winged, with 2 adjacent reticulate lines, both surfaces concave. Fl. Mar-Apr, fr. Jun-Aug.

This species is used medicinally.

● Forests, mountain slopes, valleys, streamsides; 600-2600 m. Chongqing, N and W Guizhou, Henan, W Hubei, Shaanxi, E and S Sichuan, C Yunnan.