细莞 xi guan

Scirpus setaceus Linnaeus, Sp. Pl. 1: 49. 1753; Schoenoplectus setaceus (Linnaeus) Palla.

Rhizomes creeping. Culms 3-12 cm tall, ca. 5 mm thick, terete, grooved. Leaves sometimes with only a sheath; leaf blade linear, usually shorter than culm, 0.2-0.5 mm wide, sometimes very short and deltoid or absent. Involucral bract 1(or 2), ovate-lanceolate, 3-10(-12) mm, spreading to erect, both surfaces dark red at base, apex long awned or mucronate. Inflorescence a pseudolateral head with 1-3 spikelets. Spikelets ovoid, 2.5-4 mm, many flowered. Glumes ovate to subelliptic, ca. 1.5 mm, both surfaces dark purple to purple, midvein greenish to straw-colored, apex rounded to obtuse. Perianth bristles absent. Stamens 2; filaments short, thick, with brown minute spots; anthers oblong, 0.3-0.5 mm; connective apex evident beyond anthers. Style short; stigmas (2 or)3, slender. Nutlet pale brown to orangish brown, broadly obovoid to subspherical, ca. 0.5 mm, plano-convex to compressed 3-sided, each surface prominently longitudinally ribbed, with many fine transverse ridges. Fl. and fr. Jun-Aug. 2n = 28.

Stream margins, pond margins, moist grassy slopes, floodplains; 1800-4600 m. Gansu, Jiangxi, Ningxia, Qinghai, Shaanxi, Sichuan, Xinjiang, Xizang, Yunnan [Afghanistan, Bhutan, India (Sikkim), Kashmir, Kazakhstan, Kyrgyzstan, Myanmar, Nepal, Pakistan, Russia, Tajikistan, Thailand, Uzbekistan; Africa, SW Asia, Atlantic Ocean islands, Australia, Europe, North America].