18. Cyperus niveus Retzius, Observ. Bot. 5: 12. 1788.
南莎草 nan suo cao
Perennials. Rhizomes short, thickened. Culms tufted, 10-70 cm tall, 3-angled, smooth, base slightly swollen into a bulb shape. Leaves shorter than or sometimes as long as culm; leaf blade 2-3 mm wide, usually folded but sometimes flat. Involucral bracts 2 or 3, leaflike, longer than inflorescence. Inflorescences capitate, 2-3 cm in diam., with 6 to more than 20 spikelets. Spikelets narrowly oblong-ovoid to narrowly ovoid, 0.7-2(-2.5) cm × 3-5 mm, compressed, 8-48-flowered; rachilla wingless. Glumes yellowish white to pale straw-colored on both surfaces but adaxially usually pale rusty brown and with short striae, densely imbricate, ovate-lanceolate, 4-4.5 × ca. 2 mm, papery, conspicuously many veined, midvein green, apex subobtuse. Stamens 3; anthers linear; connective not prominent beyond anthers. Style long; stigmas 3, shorter than style. Nutlet broadly obovoid, ca. 1/3 as long as subtending glume, triquetrous. Fl. and fr. Sep-Oct. 2n = 64, 68, 74.
Sand at stream margins, mountain slopes, wet places; 500-2100 m. Sichuan, SE Xizang, Yunnan [Afghanistan, Bhutan, India, Kashmir, N Myanmar, Nepal, Pakistan, Thailand, Vietnam; tropical Africa, SW Asia].