Description from Flora of China
Persicaria jucunda (Meisner) Migo; Polygonum hangchouense Matsuda.
Herbs annual, 60-90 cm tall. Stems erect, usually prostrate at base, glabrous, much branched. Petiole 3-6 mm; leaf blade elliptic-lanceolate, 6-10 × 1.5-2.5 cm, both surfaces sparsely appressed-hispidulous or subglabrous, shortly ciliate at margin, base cuneate, margin entire, apex acuminate; ocrea brownish, tubular, 5-10 mm, membranous, sparsely appressed hispidulous, apex truncate, cilia 6-11 mm. Inflorescence terminal or axillary, spicate, dense, 3-6 cm; bracts green, funnel-shaped, cilia 1.5-2 mm, each bract 3-5-flowered. Pedicels longer than bracts, 7-8 mm. Perianth pinkish or white, 5-parted; tepals oblong, 2-3 mm. Stamens 7 or 8, shorter than perianth. Styles 3, connate to below middle, longer than perianth, or stamens longer than perianth and styles shorter than perianth on separate plant; stigmas capitate. Achenes included in persistent perianth, black, shiny, ovoid, trigonous, ca. 2.5 mm. Fl. Aug-Sep, fr. Sep-Nov. 2n = 20*.
* Grassy slopes, moist valleys, along ditches; sea level to 2000 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang.