Description from Flora of China
Persicaria maackiana (Regel) Nakai ex T. Mori; Polygonum thunbergii Siebold & Zuccarini var. maackianum (Regel) Maximowicz ex Franchet & Savatier; Tracaulon maackianum (Regel) Greene; Truellum maackianum (Regel) Soják.
Herbs annual. Stems erect or ascending, 30-80 cm tall, angulate, much branched, retrorsely prickly and densely stellate hairy. Petiole 1-5 cm, retrorsely prickly and densely stellate hairy; leaf blade narrowly hastate, 3-8 × 2-4 cm, both surfaces densely stellate hairy and sparsely prickly, base cordate, apex acute; ocrea tubular, apex with herbaceous wing; wing orbicular, margin dentate. Inflorescence terminal or axillary, capitate; peduncle branched, densely stellate hairy and sparsely glandular hairy; bracts lanceolate, usually densely stellate hairy, each 2-flowered. Pedicels shorter than bracts. Perianth pinkish, 5-parted; tepals broadly elliptic, ca. 4 mm. Stamens 8, in 2 whorls, included. Styles 3, connate to below middle. Achenes included in persistent perianth, deep brown, shiny, ovoid, trigonous, ca. 3.5 mm. Fl. Jun-Sep, fr. Jul-Oct.
Shaded grassy places in valleys; 100-1600 m. Anhui, Guangdong, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shaanxi, ?Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Korea, Russia (Far East)].