Description from Flora of China
Persicaria limicola (Samuelsson) Yonekura & H. Ohashi.
Herbs annual. Stems stoloniferous, 40-80 cm, much branched at base, glabrous, rooting from nodes. Petiole 2-3 mm; leaf blade elliptic-lanceolate or ovate-lanceolate, 2-4 × 1-2 cm, both surfaces sparsely appressed hispid, densely so along midvein, base broadly cuneate, margin shortly ciliate, apex acute; ocrea tubular, 5-10 mm, membranous, apex truncate, cilia 5-8 mm. Inflorescence terminal, spicate, dense, 1.5-3 cm; bracts green, funnel-shaped, ca. 3 mm, cilia 1-1.5 mm. Pedicel 5-6 mm, slender. Perianth pinkish or white, 5-parted; tepals elliptic, 3-3.5 mm. Stamens 8, equaling or shorter than perianth. Styles 3, connate to below middle; stigmas capitate. Achenes included in persistent perianth, black-brown, shiny, ovoid, trigonous, 2.5-3 mm. Fl. Sep-Oct, fr. Oct-Nov.
* Valleys, humid places along ditches; 100-300 m. Guangdong, Guangxi, Hubei, Hunan, ?Yunnan.