Vines annual or sometimes perennial (in S China), climbing. Stem branched, terete, 1--2 m, herbaceous or slightly woody near base, smooth or pubescent, hollow and slightly pithy. Petiole 0.7--2 cm, scarcely winged; abscission zone distal; tendrils usually present. Leaf blade usually ovate to elliptic, 7--15 × 5--11 cm, herbaceous, abaxially glabrous, papillose-puberulent, or pubescent. Inflorescence of 1 umbel, basally not prophyllate; peduncle rather slender, 3--5(--10) cm, slightly compressed; umbels of both sexes 5--20(--30)-flowered, base thickened; bracteoles 1--2 mm, not caducous. Male flowers: tepals yellowish green, 4--5 × 0.6--1 mm; stamens 4--5 mm. Female flowers: tepals slightly smaller than male ones. Berries blue-black, globose, 7--9 mm in diam. Fl. Jun--Jul, fr. Oct.

Forests, thickets, grassy slopes, hillsides along valleys; near sea level to 2100 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, ?Nei Mongol, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Korea, Philippines].