Description from Flora of China
Schoenus ruber Loureiro, Fl. Cochinch. 1: 41. 1790; Morisia wallichii Nees; Rhynchospora wallichii (Nees) Kunth.
Annuals or short-lived perennials. Rhizome short. Culms tufted, 30-65 cm tall, 0.8-2 mm thick, terete, smooth. Leaves shorter than culm; sheath brownish straw-colored, 1-7 cm; leaf blade narrowly linear, 1.5-3.5 mm wide, papery, slightly scabrous, apex acuminate. Involucral bracts 4-10, stiffly spreading, leaflike, 1-5(-8.5) cm, longer than inflorescence, unequal, densely ciliate at dilated base, sheathless. Inflorescence a single terminal head, brown to orangish brown, globose, 1-1.8 cm in diam., with many spikelets. Spikelets narrowly ovoid, 6-8 mm, shiny, 2-4-flowered. Glumes 7 or 8, brown, ovate-lanceolate to elliptic-ovate, thinly papery, keeled, vein 1, apex obtuse to acute; basal glumes each with a female flower; apical 1 or 2 glumes each with a male flower. Perianth bristles 4-6, unequal, 1/3-1/2 as long as nutlet, antrorsely scabrous. Stamens 2 or 3; filaments shorter to longer than subtending glume; anthers linear; connective evident. Style filiform; stigmas 2 or sometimes undivided, very short. Nutlet brown when mature, obovoid, 1.5-1.8 mm, biconvex, edges subacute with apical half hispid-serrulate, sides sparsely hispid-scabrous mainly on apical half, obscurely spotted with minute isodiametric epidermal cells; persistent style base conic, 1/5-1/4 as long as nutlet, base abruptly widened. Fl. and fr. May-Nov.
Plants from China would be Rhynchospora rubra subsp. rubra; other subspecies occur in Africa and Madagascar.
Road margins, grassy slopes, wet places; 100-1400 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Taiwan, S Yunnan, Zhejiang [India, Indonesia, Japan, Korea, Laos, Malaysia, Nepal, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Australia, Indian Ocean islands, Madagascar, Pacific islands].