Herbs perennial, stoloniferous, subglabrous, monoecious or dioecious. Stems 30-100(-200) cm tall, succulent distally, with galls on mid portion of internodes. Stipules soon deciduous or subpersistent, green or brownish, oblong, 7-25 mm, herbaceous or membranous, obtuse at apex; petiole subequal in length, 2-9 cm; leaf blade abaxially pale green, adaxially dark green, ovate, ovate-elliptic, or oblong-lanceolate, subequal in size, 7-23 × 3-7 cm, herbaceous, 3-veined, lateral veins many, distal veins anastomosing, cystoliths on both surfaces, base rounded, rarely subcordate, margin coarsely serrate or coarsely dentate-serrate, apex acuminate, acumen entire or serrulate. Inflorescences in pairs, male a dense paniculate cyme, 1-2 cm; female ones of lax flowers, 2-5 cm. Male flowers greenish, pedicellate, in bud ca. 2 mm; perianth lobes 4, obovate-oblong, apex acute, subapically corniculate; stamens 4; rudimentary ovary small. Female perianth lobes greenish, connate to apex, equal, semiorbicular or broadly ovate, 1/3-1/2 as long as fruits, apex obtuse; staminodes oblong. Achene green to dark brownish, broadly ovoid, 1.2-1.6 mm, slightly compressed, oblique at apex, spinulosely verrucose, enclosed by persistent lobes. Fl. Jun-Oct, fr. Sep-Dec.

Moist places in broad-leaved forests; 300-2300(-2700) m. Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, SW Jiangsu, Jiangxi, S Shaanxi, Sichuan, Taiwan, SE Xizang, Yunnan, Zhejiang [India, Indonesia, Japan, Sri Lanka, Vietnam].