5. Cyperus trialatus (Boeckeler) J. Kern, Reinwardtia. 3: 32. 1954.
三翅秆砖子苗 san chi gan zhuan zi miao
Scirpus trialatus Boeckeler, Flora 42: 445. 1859; Cyperus turgidulus C. B. Clarke; Mariscus trialatus (Boeckeler) Tang & F. T. Wang.
Perennials. Rhizomes short, hardened. Culms 35-70 cm tall, compressed triquetrous, smooth, winged at angles, with several leaves at basal part. Leaves shorter to slightly longer than culm; leaf blade 0.8-1.2 cm wide, flat, smooth. Involucral bracts 3-5, leaflike, basal 2 or 3 longer than inflorescence, subspreading. Inflorescence a compound or sometimes simple anthela; rays 8-10, to 5.5 cm, each with 2-7(-16) raylets; raylets mostly to 1.5 cm. Glomerules of 5-18 spikelets densely arranged at apex of rays and raylets, 5-8 mm in diam. Spikelets ovoid to oblong-ovoid, 3-5.5 × 1.8-2.5 mm, slightly turgid, 6-10-flowered; rachilla wingless. Glumes brown to brownish on both surfaces, densely imbricate, broadly ovate, 2-2.5 mm, membranous, concave, 13-15-veined, keel abaxially green, apex excurved mucronate. Stamens 3; anthers broadly linear, ca. 0.8 mm. Style ca. 0.2 mm; stigmas 3, ca. 1 mm. Nutlet dark brown, sessile, ovoid, ca. 1.8 mm, 3-sided, densely punctate, apex subacute. Fl. and fr. Jun-Jul.
Shaded places under sparse forests or scrub, grasslands by water, field margins; 100-500 m. Guangdong, Hainan [Indonesia, Malaysia, Thailand, Vietnam].