483. Carex fluviatilis Boott, Ill. Gen. Carex. 4: 172. 1867.
溪生薹草 xi sheng tai cao
Carex yungningensis Handel-Mazzetti & Kükenthal.
Rhizome short, indurate. Culms tufted, 10-70 cm tall, trigonous, erect, stiff, clothed with brown-reddish sheaths at base. Lower involucral bracts leaflike, much surpassing inflorescence. Spicate inflorescence long cylindric or ovate-elliptic, 1.5-3.5 × 0.8-1.3 cm, dense at apex, lower 1 or 2 usually distant; spikes numerous, androgynous, ovate, 5-7 mm. Female glumes pale, light green at middle, ovate-lanceolate, 2.5-3 × 1.2-1.5 mm, membranous, apex acuminate, awned. Utricles pale green, longer than glume, ovate-lanceolate or oblong-elliptic, plano-convex, 3-3.5 × ca. 1.5 mm, membranous, glabrous, many veined on both faces, margins from middle to apex with narrow serrulate wings, apex gradually narrowed into a medium-sized beak, orifice 2-toothed. Nutlets pale brown, loosely enveloped, ovate or suborbicular, plano-convex, 1.3-1.5 mm, lustrous; stigmas 2. Fl. and fr. Jun-Sep.
Wet places in forests and streamsides along valleys; 1300-3200 m. Guizhou, Sichuan, Xizang, Yunnan [India, Myanmar].