Description from Flora of China
Cyperus metzii (Hochstetter ex Steudel) Mattfeld & Kükenthal; Kyllinga metzii Hochstetter ex Steudel; K. squamulosa Kunth.
Annuals. Roots fibrous. Culms densely tufted, 2-20 cm tall, slender, compressed triquetrous, smooth, base not swollen. Leaves equaling or slightly shorter than culm; sheath brownish purple, basal 1 or 2 bladeless; leaf blade 2-3 mm wide, flaccid. Involucral bracts 3 or 4, leaflike, much longer than inflorescence, spreading to downward reflexed, base usually broadening. Spike 1(-3), subglobose, 6-9 mm in diam., with many spikelets. Spikelets densely congested, broadly ovoid, 2.5-3 × 1.5-2 mm, compressed, 1-flowered. Glumes pale to straw-colored and sometimes rusty brown maculate, boat-shaped, 2.5-3 mm, keel green, winged, with 6-10 slightly broad teeth shaped like a cockscomb on apical ca. 2/3 of margin, and 1-3 spinelike trichomes at apex of teeth, apex with a strict mucro. Stamens 1 or 2; anthers oblong. Style of medium length; stigmas 2. Nutlet at first yellow but dark brown when mature, ellipsoid, ca. 2/3 as long as subtending glume, compressed, with dense punctate processes. Fl. and fr. Aug-Oct. 2n = 14.
Kyllinga squamulata is naturalized in SE North America and the Caribbean.
Wet grasslands, forests in valleys; 2300-3000 m. SW Sichuan, Yunnan [Bhutan, India, Nepal, Pakistan, Vietnam; tropical Africa, NE Australia, Madagascar].