Description from Flora of China
Carex brunnea var. nakiri Ohwi; C. sendaica Franchet var. nakiri (Ohwi) Koyama.
Rhizome short, without stolons. Culms densely tufted, slender, 40-70 cm tall, triquetrous, smooth, many leaved at base. Leaves longer or shorter than culm, blades 2-3 mm wide, conduplicate proximally, distally gradually flattened, scabrous on both surfaces and margins, sheathed; sheaths short, usually less than 5 cm, splitting at membranous part. Involucral bracts sheathed, lower involucral bracts blades leaflike, upper blades setaceous; sheaths 7-20 mm, brownish green. Spikes few to more than 10, usually 1 or 2 in an involucral bract sheath, not branched, distance between 2 spikes up to more than 10 cm, spikes androgynous, male part much shorter than female part, cylindric, 1.5-3 cm, densely many flowered, pedunculate; peduncles short at upper part, long at lower part. Female glumes yellowish brown, shortly brown striate, ovate, ca. 2.5 mm, membranous, 3-veined, apex acute or obtuse, muticous. Utricles brown, suberect, longer than glume, elliptic or suborbicular, compressed plano-convex, 3-3.5 mm, membranous, thinly 9-veined abaxially, white hispidulous on both surfaces, base abruptly contracted into a short stipe, apex abruptly narrowed to a short beak, beak less than 1 mm, 2-toothed at orifice. Nutlets yellow-brown, tightly enveloped, suborbicular, compressed biconvex, base estipitate; style base slightly thickened; stigmas 2. Fl. and fr. Jun-Oct.
Mountain slopes, forests or among shrubs in valleys, riversides, shady places at roadsides, sunny places at watersides; 200-1800 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [India, Japan, Korea, Nepal, Philippines, Vietnam; Australia].