Description from Flora of China
Herbs perennial, 70-120 cm tall. Stem green or tinged purple, angulate or quadrangular, appressed or spreading pubescent, or nearly glabrous; branches opposite. Petioles 0.5-3 cm, hairy; leaf blade elliptic or elliptic-lanceolate, rarely oblanceolate, 4.5-12 × 2-7.5 cm, both surfaces annexed or spreading pubescent, base cuneate or broadly cuneate, caudate. Spikes terminal or axillary, 3-5 cm; rachis 1-2 cm, white hairy. Flowers dense, ca. 5 mm. Bracts reflexed after anthesis, broadly ovate, 2-3 mm, apex acuminate; bracteoles 2.5-3 mm, spiny, base 2-parted, apex curved. Tepals shiny, lanceolate, 3-5 mm, with a midvein, apex acute. Stamens 2-2.5 mm; pseudostaminodes slightly serrulate, apex rounded. Utricles yellowish brown, shiny, oblong, 2-2.5 mm, smooth. Seeds light brown, oblong, ca. 1 mm. Fl. Jul-Sep, fr. Sep-Oct. 2n = 42, 84*.
Hillsides; 200-1800 m. Anhui, Fujian, Hebei, Hunan, Guangxi, Guizhou, Hubei, Jiangsu, Shaanxi, Shanxi, Sichuan, Taiwan, Xizang, Zhejiang [Bhutan, India, Indonesia, Japan, Korea, Laos, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Russia, Sikkim, Thailand, Vietnam].