胀囊薹草 zhang nang tai cao

Rhizome stoloniferous, stolons branched. Culms 30-100 cm tall, ± stiff, triquetrous, scabrous on upper part, with red-brown and bladeless sheaths at base, rudimentary sheaths usually disintegrating into reticulate fibers. Leaves slightly shorter than culm, blades 2-5 mm wide, flat, ± stiff, with transverse septate nodes between veins, sheathed. Involucral bracts leaflike, lowermost shortly sheathed, upper not sheathed. Spikes 4-6, remote; terminal 2 or 3 spikes male, approximate, linear-cylindric, 2-3.5 mm, subsessile; remaining spikes female, oblong or oblong-cylindric, 3-7 × 1-1.5 cm, densely many flowered, shortly pedunculate. Female glumes pale ferruginous or ferruginous, narrowly ovate or ovate-lanceolate, ca. 3.2 mm, membranous, 3-veined, yellow-green between veins, margins white hyaline, apex acuminate and muticous. Utricles yellowish green, obliquely patent, longer than glume, ovate or conic-ovate, inflated trigonous, 6-8 mm, subleathery, slightly nitid, glabrous, several veined, base rounded, shortly stipitate, apex attenuate into a short beak, orifice 2-toothed. Nutlets rather loosely enveloped, obovate, trigonous, 1.7-2 mm, base stipitate; style slender, usually flexuose, base not thickened; stigmas 3, rather short. Fl. and fr. May-Jul.

Wet places at riversides, at lakesides, in swamps, or in meadows. Heilongjiang, Jilin, Liaoning, Nei Mongol [Japan, Korea, Mongolia, Russia; Europe, North America].

This plant is used as forage and for making paper.