Description from Flora of China
Parietaria coreana Nakai; P. debilis var. micrantha (Ledbour) Weddell; P. lusitanica Linnaeus subsp. chersonensis (Lang) Chrtek var. micrantha (Ledbour) Chrtek.
Herbs weakly annual, diffuse, 10-40 cm tall, strigillose. Petiole slender, 0.4-2 cm; leaf blade ovate or ovate-cordate, 0.5-3 × 0.4-2.2 cm, membranous, secondary vein 1 on each side of basal midvein, sparsely pubescent abaxially, base rounded or subcordate, apex acute or obtuse. Flowers ca. 1.5 mm in diam., in small clusters; bracts green, linear, simple at base of pedicel or 3 basally connate and subtending base of perianth, covered with glandular hairs, in fruit enlarged to 1.5 mm. Bisexual flowers: pedicel 0.6 mm; perianth lobes 4, brown-green, oblong-ovate, membranous; stamens 4; stigma penicillate. Female flowers pedicellate or sessile; perianth lobes 4, connate into a campanulate tube, light brown, thinly membranous; lobes deltoid. Achenes black, ovoid, 1-1.3 mm, very smooth, lustrous. Fl. Jun-Jul, fr. Aug-Oct.
The plants are used as medicines to draw out pus and reduce swelling.
Shady, wet places, rocky mountain slopes, grasslands, wall of villages; 700-3500(-4000) m. Anhui, Beijing, S Gansu, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan [Bhutan, N India, Japan, Korea, Mongolia, Nepal, Russia (Siberia), Sikkim; N Africa, C and SW Asia, Oceania, South America].