三棱水葱 san leng shui cong

Scirpus triqueter Linnaeus, Syst. Nat., ed. 12, 2: 83; Mant. Pl. 29. 1767; Schoenoplectus trisetosus (Tang & F. T. Wang) S. Yun Liang; Scirpus trisetosus Tang & F. T. Wang.

Rhizomes long creeping, reddish brown, slender. Culms solitary, erect, 20-100 cm tall, 2-8 mm thick, 3-angled, subrigid, clothed at base with 2 or 3 leaf sheaths. Leaf sheath pale green, 5-15 cm, membranous, distinctly transversely septate, mouth obliquely truncate; leaf blade flat, 1.3-5.5(-8) cm × 1.5-2 mm. Involucral bract 1, culmlike, 1.5-7 cm, 3-angled, usually shorter than inflorescence, apex subacute. Inflorescence a pseudolateral anthela, 3-6 cm, laxly bearing 3-20 spikelets or sometimes congested in a headlike cluster; rays to 5 cm, ± stout, scabrous. Spikelets oblong to ovoid-oblong, 6-12 × 3-7 mm, densely many flowered, apex obtuse. Glumes yellowish brown, elliptic, oblong, or broadly ovate, 3-4 mm, membranous, margin sparsely ciliate, apex emarginate to rounded with a green costa excurrent into a mucro. Perianth bristles 3-5, almost as long as nutlet, retrorsely scabrous. Stamens 3; anthers linear; connective apex dark brown, evident beyond anthers. Style short; stigmas 2. Nutlet brownish at maturity, obovoid, 2-3 mm, plano-convex, shiny. Fl. and fr. Jun-Oct. 2n = 40, 42.

Wet places at river margins, ditches, pond margins, swamps; 100-2300 m. Anhui, Chongqing, Fujian, Gansu, Guangdong, N Guangxi, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jilin, Liaoning, Nei Mongol, Ningxia, E Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, S Xizang, Yunnan, Zhejiang [Afghanistan, India, Japan, Kazakhstan, Korea, Kyrgyzstan, Pakistan, Russia, Tajikistan, Uzbekistan; N Africa, SW Asia, Atlantic Ocean islands, Europe].