Description from Flora of China
Scirpus ovatus Roth, Tent. Fl. Germ. 2: 562. 1793; Eleocharis soloniensis (Dubois) H. Hara; S. soloniensis Dubois.
Annuals. Rhizomes and stolons absent. Culms densely tufted, 4-50 cm tall, slender, terete, smooth, with few longitudinal ribs. Leaf sheaths 1-3, basally slightly red and apically greenish to straw-colored, 0.5-3 cm, tubular, mouth obliquely truncate, apex acute to mucronate. Spikelet ovoid to broadly ovoid, 4-8 × 3-4 mm, densely many flowered, apex acute. Basal 2 glumes empty; basalmost glume amplexicaul for nearly 3/4 to all of spikelet base; fertile glumes greenish medially and blood-red on sides, laxly imbricate, ovate, oblong-ovate, or broadly ovate, ca. 1.5 × 0.5 mm, membranous, margin narrowly hyaline, apex acute to obtuse. Perianth bristles 6, ca. 1.5 × as long as nutlet (including style base), retrorsely spinulose. Stigmas 2. Nutlet at first white but turning brownish at maturity, obovoid, ca. 0.8 × 0.5 mm, conspicuously convex on dorsal side and slightly convex on ventral side, smooth; persistent style base deltoid, ca. 1/3 as long and ca. 1/2 as wide as nutlet, dorsiventrally compressed, not spongy, surface not mammillate, apex acuminate. Fl. and fr. Aug-Dec.
Marshy areas; 100-3600 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Yunnan [Japan, Kazakhstan, Russia; Europe, North America].