• Scientific Name: Bistorta macrophylla (D.Don) Soják
• Ref: Preslia 46:152. 1974
• Synonyms: Polygonum macrophyllum D. Don, Persicaria macrophylla (D.Don) Cubey
• English Common Name: red knotweed, large leaved knotweed
• Chinese Common Name: 圆穗拳参 yuánsuì quánshēn, 圆穗蓼 yuánsuì∙liǎo
• Family: Polygonaceae
• Genus: Bistorta
• Distribution: Grassy slopes, alpine meadows; 2300-5000 m. Guizhou, ?Henan, Hubei, Shaanxi, Sichuan, Xizang, Yunnan [Bhutan, N India, Nepal, Sikkim].
• Photo: 07/21/2011, Mt. Taibai, Qinling

Herbs perennial. Rhizomes curved, large, 1-2 cm in diam. Stems 2 or 3 from rhizome, erect, 8-30 cm tall, simple. Basal leaves petiolate; petiole 3-8 cm; leaf blade gray-green abaxially, green adaxially, oblong, lanceolate, or linear-lanceolate 3-11 × 0.2-3 cm, abaxially sometimes sparsely pubescent, adaxially glabrous, base subcordate or cuneate, margin with thickened vein tips, revolute, apex acute. Cauline leaves shortly petiolate or subsessile; leaf blade narrowly lanceolate or linear; ocrea: lower part green, upper part brown, tubular, membranous, apex oblique, dehiscent, not ciliate. Inflorescence terminal, shortly spicate, 1.5-2.5 cm, 1-1.5 cm in diam.; bracts ovate, 3-4 mm, membranous, apex acuminate, each 2- or 3-flowered. Pedicel 4-5 mm, slender. Perianth pinkish or white, 5-parted; tepals elliptic, 2.5-3 mm. Stamens 8, exserted; anthers black-purple. Styles 3, connate at base; stigmas capitate. Achenes included in persistent perianth, yellow-brown, shiny, ovoid, trigonous, 2.5-3 mm. (Flora of China)