Polygonum islandicum (Linnaeus) J. D. Hooker.
Herbs annual, dwarf. Stems erect, usually tufted, reddish, 3-8 cm tall, slender, glabrous; branches spreading. Leaves alternate, rarely opposite above; petiole 1-3 mm, glabrous; leaf blade broadly elliptic, obovate, or nearly orbicular, 3-5 × 2-4 mm, both surfaces glabrous, sparsely puncticulate, base broadly cuneate, margin entire, apex obtuse; ocrea lax, brown, 1.5-2 mm, thinly membranous. Flowers axillary, fascicled. Perianth greenish, 3-parted; tepals broadly elliptic, ca. 1 mm. Stamens 3, shorter than perianth. Styles 2 or 3, very short; stigmas 2(or 3), capitate. Achenes brown, dull, 1.2-1.5 mm, granular. Fl. Jul-Aug, fr. Aug-Sep. 2n = 28.
Alpine meadows, wet grasslands, valleys; 2000-4900 m. Gansu, Qinghai, Shanxi (Wutai Shan), Sichuan, Xinjiang, Xizang, Yunnan [Bhutan, NW India, Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Sikkim; Arctic regions, N Europe, North America].
