Description from Flora of China
Perennials. Rhizomes slender, long creeping, clothed with brown, membranous scales, internodes 1-2.5 cm, with 1 culm at each node. Culms serially arranged, sometimes also laxly tufted, 2-30 cm tall, compressed 3-angled, smooth, base not swollen, with 4 or 5 leaf sheaths. Leaves shorter to slightly longer than culm; sheaths brown, mouth obliquely truncate, apex acuminate, basal 2 bladeless, apical 2 or 3 with a blade; leaf blade 5-15 cm × 2-4 mm, flaccid, flat, midvein and apical margin spinulose. Involucral bracts 3, leaflike, longest erect to oblique or horizontal. Spike 1(-3), globose to ovoid-globose, 5-11 × 4-10 mm, with numerous densely arranged spikelets. Spikelets narrowly oblong-ovoid to narrowly ovoid, ca. 3 × 1 mm, compressed, 1- or 2-flowered. Glumes white and rusty brown maculate or rarely straw-colored, ovate, 2.8-3 mm, keel spinulose or not, veins 2 or 3 on each side of keel, apex with a strict or recurved mucro or not mucronate. Stamens 1-3; anthers linear, ca. 0.7 mm. Style long; stigmas 2, less than 1/2 as long as style. Nutlet obovoid-oblong, 1-1.5 mm, biconvex, densely punctate. Fl. and fr. May-Oct.
Kyllinga brevifolia var. yunnanensis E. G. Camus (Notul. Syst. (Paris) 1: 239. 1910) could not be treated here because no material was seen by the present authors.
Under shrubs or forests, grasslands, swamps, meadows, mountain slopes, valleys, wet places along trails, ditch margins, shallow water, river margins, wet places at seashores, paddy field margins; near sea level to 2800 m. Anhui, Chongqing, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xisha Qundao, S and SE Xizang, Yunnan, Zhejiang [Afghanistan, Bangladesh, Bhutan, India, Indonesia, Japan, Korea, Laos, Malaysia, Myanmar, Nepal, Pakistan, Papua New Guinea, Philippines, Russia (Far East), Sri Lanka, Thailand, Vietnam; tropical Africa, Atlantic Ocean islands, Australia, Central, North, and South America, Indian Ocean islands, Madagascar, Pacific islands].