Description from Flora of China
Scirpus ciliaris Linnaeus, Mant. Pl. Alt. 182. 1771; Fuirena glomerata Lamarck; F. rottboellii Nees.
Annuals. Rhizomes short. Culms tufted, 7-40 cm tall, 3-angled, striate-sulcate, pubescent, clothed at base with 1 or 2 bladeless pubescent leaf sheaths. Cauline leaves with sheath 1-3.5 cm; ligule rust-colored to reddish, 1-2 mm, membranous, mouth truncate; leaf blade linear, 5-15 × 3-7 mm, flat, soft, 3-costate, surfaces and margin ± pubescent, apex acuminate. Involucral bracts leaflike, surpassing inflorescence; bractlets setaceous, sheathless. Inflorescences with 1-3 clusters of spikelets, interrupted, glomerulate, 1-3 cm wide, bearing 3-15 spikelets; peduncles single, mostly enclosed in bractlet sheaths. Spikelets ovoid to oblong, 5-8 × 2.5-3 mm, many flowered, covered with woolly hairs. Glumes basally yellowish brown, apically grayish black, obovate, 1.2-2 mm, thinly membranous, abaxially pilose, apex obtuse, emarginate, and with a 3-veined costa excurrent into a recurved 1-1.5 mm awn. Perianth bristles 6; 3 outer bristles needlelike, occasionally much reduced, retrorsely scabrous; 3 inner bristles brownish, with subquadrate blades abruptly narrowed at base to a distinct ca. 0.3 mm stalk, apex mucronulate. Stamens 3; anthers oblong, 0.2-0.3 mm. Ovary white, oblong, 3-sided; style brownish, 3-4 × as long as ovary; stigmas 3, 1/3-1/2 as long as style. Nutlet brownish, shortly stipitate, obovoid, ca. 1 mm, 3-sided. Fl. and fr. Jul-Dec. 2n = 38.
Wet places, often in paddy fields, river margins; near sea level to 200 m. Fujian, Guangdong, S Guangxi, Hainan, Hebei, Jiangsu, Shandong, Taiwan, S Yunnan [Bangladesh, Cambodia, India, Indonesia, Japan, Korea, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Australia].