1. Bolboschoenus yagara (Ohwi) Y. C. Yang & M. Zhan, Acta Biol. Plateau Sin. 7: 14. 1988.
荆三棱 jing san leng
Scirpus yagara Ohwi, Mem. Coll. Sci. Kyoto Imp. Univ., Ser. B, Biol. 18: 110. 1943; S. fluviatilis (Torrey) A. Gray var. yagara (Ohwi) T. Koyama.
Rhizomes long creeping, blackish brown, 3-6 mm thick, terminated by a tuber; tuber globose to depressed obovoid, 2-3 × 3-4 cm, woody, covered with blackish to purplish brown membranous broad scales. Culms solitary from a tuber, 0.6-1.5 m tall, sharply 3-angled, smooth. Leaves as long as or overtopping culm; sheath 5-20 cm, front with veins nearly to summit (i.e., lacking veinless area); blade broadly linear, 5-10 mm wide, ± stiff, margin scabrous. Involucral bracts 3 or 4, leaflike, usually longer than inflorescence. Inflorescence a simple anthela; rays 3-8, unequal, to 7 mm, smooth, each terminated by a single spikelet or a cluster of 2 or 3(or 4) spikelets. Spikelets rust-colored brown, ovoid to oblong, 1-2 × 0.5-0.8(-1) cm, many flowered. Glumes rust-colored brown, densely imbricate, oblong, ca. 7 mm, membranous, abaxially minutely pubescent, 1-veined costa projected beyond apex forming a recurved 2-3 mm scabrous awn, apex 2-cleft and lacerate. Perianth bristles 6, almost as long as nutlet, retrorsely scabrous. Stamens 3; anthers linear, ca. 4 mm. Style slender; stigmas 3. Nutlet grayish brown, obovoid, 3-sided, base cuneate-attenuate, apex contracted to a conic short beak. Fl. and fr. May-Jul.
Lake margins, shallow water, marshes, wet places; near sea level to 200 m. Anhui, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jilin, Liaoning, NE Nei Mongol, Shandong, Xinjiang, Yunnan, Zhejiang [India, Japan, Kazakhstan, Korea, Russia, Vietnam; Europe].