Description from Flora of China
Schoenus nemorum Vahl, Symb. Bot. 3: 8. 1794; Hypolytrum formosanum Ohwi; H. latifolium Persoon.
Roots few, hard, fibrous. Rhizomes short, slightly thick, woody, with dense reddish scales. Culms central, 30-90 cm tall, 3-4 mm thick, 3-angled, stiff. Leaves basal and 1 or 2 cauline, longer than culm; basal leaf sheath brownish, 5-15 cm, margin thickly membranous, basal few bladeless; leaf blade 35-120 × 0.8-2.6 cm or longer, flat, stiff, subleathery, base folded, margin scabrous near apex. Involucral bracts 3-5, leaflike, at base of inflorescence and branches, basalmost much longer than inflorescence, not sheathing. Inflorescences paniculate, ovoid-globose to subglobose, 3-7 × 4.5-6 cm, with many spikes; rachis and rachilla angles scabrous. Spikes obovoid, becoming globose when mature, 3-7 × 3-6 mm, with many glumelike bracts. Glumelike bracts brown, spirally and imbricately arranged, obovate, ca. 2 mm, mid-veined, each subtending a pseudospikelet, apex rounded and mucronate. Pseudospikelets ca. 1.5 mm, with 2 glumes, 2 male flowers, and 1 female flower; glumes brown, lateral and opposite, cymbiform, ca. 1.2 mm, membranous, keeled, connate on adaxial side, spinulose on keel, each with a male flower. Filaments slender; anthers narrowly oblong. Stigmas 2. Nutlet dark grayish brown, subglobose, 2-2.5 mm (including rostrum), compressed, longitudinally rugose, apex conically rostrate. Fl. and fr. Apr-Aug.
Wet places in forests or scrub, valleys; 100-1200 m. Fujian, Guangdong, Guangxi, Hainan, Taiwan, Yunnan [Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; tropical Africa and America, NE Australia, Indian Ocean islands, Pacific islands].