Plants 10-40 cm tall. Stem erect, much branched, densely hairy; lower branches ascending or subprostrate. Leaves linear or oblanceolate, 1.5-4 cm × 4-8 mm, 1-veined, hairy, base attenuate, apex acute, mucronate. Spikelike inflorescence elongate, 5-15 cm; bracts linear, lanceolate, or ovate, 0.4-1.7 cm × 1.5-2.5 mm, hairy, base attenuate or rounded, margin narrowly membranous, apex acute or acuminate. Perianth segments 1(or 3), upper one oblong, apex acute. Stamens 1(or 3). Utricle gray-green, elliptic, 2.5-3 × 1.5-2 mm, glabrous, base broadly cuneate, apex rounded; wing yellow-green, narrow, margin entire or erose; beak terete, apex erect. Fl. and fr. Jul-Sep.

Plants with pubescent utricles but otherwise almost identical to C. heptapotamicum were described as C. korovinii Iljin (Izv. Glavn. Bot. Sada SSSR 28: 641. 1929). Such plants may be found in W Xinjiang.

Sandy places, dunes. W Gansu, S Xinjiang [E Kazakhstan].