库地薹草 ku di tai cao

Rhizome stout, long creeping, indurate. Culms 20-38 cm tall, trigonous, scabrous above, clothed with brown bladeless sheaths at base. Leaves shorter than culm, blades linear, 3-3.5 mm wide, flat, stiff, margins scabrous. Involucral bracts glumelike. Spicate inflorescence oblong or ovate, 1.5-2 cm, dense; spikes numerous, androgynous, ovate, 5-7 × ca. 4 mm. Female glumes ferruginous, ovate, ca. 2.5 × 1.5 mm, 1-veined, margins pale hyaline, apex acute. Utricles stramineous, longer than glume, ovate or ovate-lanceolate, plano-convex, 2.8-3.5 × ca. 1.2 mm, leathery, glabrous, scabrous above, many veined on both faces, veins conspicuously raised, base subrounded, shortly stipitate, margins winglike, thickened, apex abruptly contracted into a ferruginous, scabrous beak, orifice white hyaline, deeply cleft abaxially, shallowly cleft adaxially, 2-toothed. Nutlets brown, tightly enveloped, elliptic or ovate, plano-convex or compressed trigonous; style slightly thickened; stigmas 2. Fl. and fr. Jul-Aug.

Shallow water of rivers, swamps, forest margins; 1900-2500 m. Xinjiang [N Mongolia, Russia (Siberia)].