488. Carex diandra Schrank, Cent. Bot. Anmerk. 49 ["57"]. 1781.
圆锥薹草 yuan zhui tai cao
Rhizome shortly creeping, indurate. Culms loosely tufted, 30-45[-90] cm tall, compressed trigonous, scabrous above, clothed with brown or dark brown bladeless sheaths at base. Leaves shorter than culm, blades linear, 2-3 mm wide, flat, margins scabrous, apex acuminate. Involucral bracts setaceous, shorter than inflorescence. Inflorescence spicate-paniculate, 2-3.5 cm; sometimes lowest spike ± branched; spikes androgynous, broadly ovate, 5-7 mm. Female glumes ferruginous-brown, broadly ovate, ca. 3 × 2 mm, 3-veined, margins pale hyaline, apex acuminate. Utricles ferruginous-brown, greenish above, subequaling glume, broadly ovate, plano-convex, ca. 3 × 2 mm, leathery, with 4 or 5 short veins at base abaxially, nerveless adaxially, base broadly subcordate, spongy, shortly stipitate, distal margins denticulate, apex gradually contracted into a serrulate-margined and narrowly winged beak ca. 1 mm. Nutlets tightly enveloped, obovate, plano-convex, ca. 1.4 × 1.2 mm, base broadly cuneate, shortly stipitate; style base slightly thickened; stigmas 2. Fl. and fr. Jul. 2n = 48, 50, 54, 60.
Alpine lakes, marshes, boggy meadows. Nei Mongol [Russia (Far East, Siberia); C and SW Asia, C and N Europe, North America, Pacific islands (New Zealand)].