Rhizome with slender stolons. Culms laxly tufted, 10-30 cm tall, triquetrous, nearly all clothed with sheaths, lower part clothed with several reddish brown and bladeless sheaths, one side of sheath usually disintegrating into reticulate fibers. Leaves longer than or equaling culm, blades 3-4 mm wide, flat or sometimes plicate, stiff, scabrous on veins and margins, sheathed. Involucral bracts leafy, longer than culm, shortly sheathed. Spikes 3-6, slightly approximate; terminal 2 or 3 spikes male, clavate or narrowly cylindric, 1.5-3.5 cm, shortly pedunculate; remaining spikes female, oblong or oblong-cylindric, 1.5-2.5 × ca. 0.8 cm, slightly laxly many flowered, usually shortly pedunculate. Female glumes brownish, sometimes ferruginous and shortly striate, green at middle, broadly ovate, ca. 5.5 mm, membranous, 3-veined, margins white hyaline, apex acuminate, mucronate or aristate. Utricles yellowish or yellowish brown, obliquely patent, ovate, inflated trigonous, 6-6.5 mm, corky, glabrous, distinctly several veined, base broadly cuneate, rather thick and shortly stipitate, apex gradually narrowed to a rather broad and short beak, orifice sanguineous and 2-toothed. Nutlets rather tightly enveloped, broadly obovate or subelliptic, trigonous, ca. 3 mm, base shortly stipitate; style ± long, base slightly thickened, usually persistent; stigmas 3. Fl. and fr. Apr-Jun.

Seaside sands. Fujian, Hebei, Jiangsu, Liaoning, Shandong, Taiwan, Zhejiang [Japan, N Korea, Russia (Far East)].