Amblygonum orientale (Linnaeus) Nakai ex T. Mori; A. orientale var. pilosum (Roxburgh ex Meisner) Nakai ex T. Mori; Lagunea cochinchinensis Loureiro; L. orientalis (Linnaeus) Nakai; L. orientalis var. pilosa (Roxburgh ex Meisner) Nakai; Persicaria cochinchinensis (Loureiro) Kitagawa; P. orientalis (Linnaeus) Spach; P. pilosa (Roxburgh ex Meisner) Kitagawa; Polygonum amoenum Blume; P. cochinchinense (Loureiro) Meisner; ?P. orientale var. discolor Bentham; P. orientale var. pilosum (Roxburgh ex Meisner) Meisner; P. pilosum Roxburgh ex Meisner; P. torquatum Bruijn.

Herbs annual. Stems erect, 1-2 m tall, robust, much branched above, densely spreading villous. Petiole 2-10 cm, spreading villous; leaf blade broadly ovate, broadly elliptic, or ovate-lanceolate, 10-20 × 5-12 cm, both surfaces densely pubescent, along veins densely villous, base rounded or subcordate, slightly decurrent, margin densely ciliate, apex acuminate; ocrea tubular, 1-2 cm, membranous, villous, margin truncate, long ciliate, usually with green leaflike wing. Inflorescence terminal or axillary, spicate, slightly pendulous, 3-7 cm, several spikes aggregated and panicle-like; bracts green, broadly funnel-shaped, 3-5 mm, pubescent, margin long ciliate, each 3-5-flowered. Pedicels longer than bracts. Flowers dimorphic. Perianth pink or white, 5-parted; tepals elliptic, 3-4 mm. Stamens 7, exserted. Styles 2, connate to below middle, included or stamens included and styles exserted on separate plant; stigmas capitate. Achenes included in persistent perianth, black-brown, shiny, nearly orbicular, biconcave, 3-3.5 mm. Fl. Jun-Sep, fr. Aug-Oct.

Roadsides, near houses, wastelands, usually cultivated in gardens; sea level to 3000 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Yunnan, Zhejiang [Bangladesh, Bhutan, India, Indonesia, Japan, Korea, Myanmar, Philippines, Russia (Far East), Sri Lanka, Thailand, Vietnam; SW Asia, Australia, Europe].