3. Kyllinga melanosperma Nees in Wight, Contr. Bot. India. 91. 1834.
黑籽水蜈蚣 hei zi shui wu gong
Cyperus melanospermus (Nees) J. V. Suringar.
Perennials. Rhizomes thick, long creeping, internodes short, clothed with brown scales, with 1 culm at each node. Culms distant, 30-120 cm tall, very compressed 3-angled to nearly compressed, smooth, base bulbous, clothed with long leaf sheaths. Leaf sheath brown, cylindric, margin scarious, mouth obliquely truncate, apex mucronate, apical 1 or 2 with a blade; leaf blade ca. 5 cm × 3-5 mm or shorter, flat, apical margin denticulate. Involucral bracts 3, leaflike, spreading to downward reflexed. Spike 1, ovoid, oblong-ovoid, or subglobose, 6-12 × 6-8 mm, with numerous densely arranged spikelets. Spikelets narrowly ellipsoid-ovoid, ca. 3 mm, 1- or 2-flowered. Glumes straw-colored with rusty brown striae, ovate-lanceolate, ca. 3 mm, 5-7-veined, keel ± spinulose, apex mucronate. Stamens 3; anthers shortly linear; connective prominent beyond anthers. Style long; stigmas 2, shorter than style. Nutlet yellowish white at first but black when mature, oblong to obovoid-oblong, ca. 1/2 as long as subtending glume, plano-convex, with dense punctate processes, apex mucronate. Fl. and fr. Apr-Sep.
Wet places along trails, water margins, sandy areas; below 100-1000 m. Guangdong, S Guangxi, Hainan, Yunnan [India, Indonesia, Malaysia, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Africa, NE Australia, Madagascar].