Aconogonon angustifolium (Pallas) H. Hara; Persicaria angustifolia (Pallas) Ronse Decraene; Pleuropteropyrum angustifolium (Pallas) Kitagawa; Polygonum acidulum Willdenow; P. alpinum var. angustissimum Turczaninow; ?P. divaricatum var. angustissimum f. glabrum Meisner; P. polymorphum Ledebour var. angustissimum Korshinsky.

Herbs perennial. Stems erect, 20-50 cm tall, branched; branches spreading, striate, glabrous. Petiole very short or nearly absent; leaf blade narrowly linear, 3-6 cm × 2-4 mm, both surfaces glabrous, midvein prominent, lateral veins inconspicuous abaxially, base narrow, margin conspicuously revolute, apex slightly obtuse; ocrea caducous, tubular, membranous, veined, dehiscent. Inflorescence paniculate, lax; rachis and branches glabrous; bracts brown, ovate, membranous, apex acute, each 1-3-flowered. Pedicel 1.5-2 mm, apex articulate. Perianth white or milky white, 5-parted; tepals elliptic, unequal, 2-2.5 mm. Stamens 8, included. Styles 3, short; stigmas capitate. Achenes included in persistent perianth, brown, shiny, ovoid-rhomboid, trigonous, 2-2.5 mm. Fl. Jul-Aug, fr. Aug-Sep.

Grassy slopes, hills; 600-1600 m. Hebei, Heilongjiang, Nei Mongol [Mongolia, Russia (Far East, E Siberia)].