Persicaria microcephala (D. Don) H. Gross var. wallichii (Meisner) H. Hara.

Herbs annual. Stems suberect or ascending, 20-30 cm tall, angulate, glabrous. Petiole 1-2 cm, not winged, usually auriculate at base; leaf blade broadly cordate or ovate-cordate, 3-5 × 2-3.5 cm, abaxially sparsely strigose, adaxially subglabrous, base subcordate, margin entire, shortly ciliate, apex acuminate; ocrea tubular, 6-8 mm, membranous, pilose, apex truncate, shortly ciliate. Inflorescence usually geminate, capitate, 5-8 mm in diam.; peduncle glabrous; bracts ovate, apex obtuse, glabrous. Perianth white, 5-parted; tepals broadly elliptic, 2-3 mm. Stamens usually 8. Styles 3, connate to below middle; stigmas capitate. Achenes black, opaque, ovoid, trigonous, 2-2.5 mm, densely punctate. Fl. Jul-Aug, fr. Aug-Oct.

Mixed forests on mountain slopes, wet valleys; 2500-3400 m. Xizang, Yunnan [NE India, Nepal, Sikkim].