Description from Flora of China
Polygonum lineare Samuelsson in Handel-Mazzetti, Symb. Sin. 7: 188. 1929.
Herbs annual. Stems erect, 30-40 cm tall, slender, branched at base, glabrous, striate. Petiole 2-4 mm; leaf blade linear, 1.5-3 cm × 2-5 mm, both surfaces glabrous, midvein promi-nent abaxially, lateral veins inconspicuous, base hastate, margin entire, revolute, apex acute; ocrea 2-3 mm, membranous, oblique, apex acute. Inflorescence racemose, dense, several racemes aggregated and panicle-like; bracts purplish, oblique, ca. 1.5 mm, each 2- or 3-flowered. Pedicels longer than bracts, slender, apex articulate. Perianth white or pinkish; tepals elliptic, ca. 1.5 mm. Stamens included. Stigmas capitate. Achenes exceeding persistent perianth, brown, shiny, broadly ellipsoid, trigonous. Fl. Aug-Oct, fr. Sep-Nov.
* Forest margins, moist valleys; 1700-2200 m. Yunnan.