China, Japan, Taiwan, Bhutan, Nepal
Herbs (5-) 30-60 cm high; rhizomes creeping, thin. Basal part of stems creeping, rooted in whorls at nodes, apical part erect, glabrous or pubescent on nodes, sometimes purplish red. Stipular sheath (0.5-) 1-2.5 cm, 1/4-1/2 as long as petiole, usually ciliate, base enlarged and slightly clasping; petiole (0.7-) 1-3.5 (-4) cm, glabrous; leaf blade broadly ovate or ovate-cordate, (1.5-) 4-10 x (1.8-) 2.5-6 cm, thinly papery, densely glandular, usually glabrous, sometimes pubescent at vein axils, usually purplish abaxially, base cordate, apex shortly acuminate; veins 5-7, basal or innermost pair arising ca. 5 mm above base, if 7-veined, then outermost pair very slender or inconspicuous; reticulate veins ± conspicuous. Inflorescences (0.4-) 1.5-2.5 (-2.7) cm x (2-) 5-6 mm; peduncles 1.5-3 cm, subglabrous; involucral bracts oblong or obovate, (5-) 10-15 x (3-) 5-7 mm, apex rounded. Bract beneath each flower linear, terete, inconspicuous. Stamens longer than ovary. Capsule 2-3 mm, with persistent styles.