241. Carex arnellii Christ, Kongl. Svenska Vetensk. Acad. Handl., n.s. 22(10) [Scheutz, Pl. Vasc. Jenis.]: 177. 1888.
麻根薹草 ma gen tai cao
Rhizome robust, ligneous, clothed with old sheaths, usually splitting into fibers. Culms densely tufted, 25-90 cm tall, triquetrous, slightly slender, smooth at lower part, upward slightly scabrous. Leaves basal, nearly equaling culm, blades 3-4 mm wide, flat, smooth on both surfaces, margins scabrous; sheaths long. Lower involucral bracts leaflike, upper blades setaceous, shorter than subtending spike; sheaths short, not up to 1 cm. Spikes 5-7; upper 2 or 3 spikes male, narrowly oblong, subsessile; lower 3 or 4 spikes female, remote, cylindric, 2-3.5 cm, loosely many flowered, peduncles slender, ± pendulous. Female glumes stramineous or brownish yellow, lanceolate-ovate, 3.5-5 mm (including arista), membranous, green 1-3-veined, scabrous on upper part of costa and margins of arista, apex acuminate and aristate, arista short or slightly long. Utricles green-yellow, obliquely patent, equaling or slightly longer than glume, elliptic or obovate-elliptic, inflated trigonous, 4-4.5 mm, papery, glabrous, shiny, nerveless, base broadly cuneate, apex abruptly contracted into a medium-sized to long beak, orifice 2-toothed. Nutlets loosely enveloped, obovate or broadly obovate, trigonous, ca. 2.5 mm, sessile, apex mucronate; stigmas 3. Fl. and fr. May-Jun.
Mountain slopes, forests, meadows, wet places by watersides; 200-1700 m. Hebei, Heilongjiang, Jilin, Nei Mongol [Japan, Korea, Mongolia, Russia].