Bistorta griffithii (J. D. Hooker) A. J. C. Grierson; Polygonum calostachyum Diels.

Herbs perennial. Rhizomes black-brown, horizontal, large, to 20 cm, 1.5-3 cm in diam. Stems 1 or 2 from rhizome, erect, 20-40 cm tall, simple, glabrous. Basal leaves long petiolate; petiole large, 6-10 cm; leaf blade slightly shiny adaxially, elliptic, 10-15 × 3-5 cm, leathery, glabrous, midvein prominent, yellow-brown pubescent, rarely glabrous abaxially, base broadly cuneate or rounded, margin with thickened vein tips, revolute, apex acuminate or acute. Cauline leaves shortly petiolate; leaf blade ovate-elliptic; uppermost leaves subsessile; ocrea tubular, 3-6 cm, membranous, glabrous, apex oblique, not ciliate. Inflorescence terminal or axillary, spicate, nutant, lax, 3-5 cm, 1.5-2 cm in diam.; bracts broadly lanceolate or narrowly ovate, 4-5 mm, each 1- or 2-flowered. Pedicel filiform, 1-1.2 cm, articulate at middle. Perianth purple-red, 5-parted; tepals narrowly elliptic, 5-6 mm. Stamens 8, included. Styles 3; stigmas capitate. Achenes included in persistent perianth, yellow-brown, shiny, narrowly ellipsoid, trigonous, 4-5 mm. Fl. Jul-Aug, fr. Sep-Oct.

Alpine meadows, rocky fissures; 3000-5000 m. Xizang, Yunnan [Bhutan, N Myanmar].