Culms (3-)10-20 cm. Leaves: blades 0.5-1.5 mm wide. Pistillate scales brown, with hyaline margins, lanceolate, 2.5-3.5(-4.5) mm, as wide and as long as or slightly shorter than and enclosing perigynia. Perigynia finely veined, at least in proximal 1/2, 3-3.8 mm; beak teeth firm or flexible. 2n = 52.
Stems (0.5-)1-1.5(-2) dm, scattered on long rhizomes; lvs crowded toward the base, slender but ±flat, (0.5-)1-1.5 mm wide; spike 1, androgynous, bractless, mostly 8-15 mm, the upper half or three-quarters staminate; pistillate scales ovate or lance-ovate, sharply acute or cuspidate, from a little shorter to a little longer than the perigynia; perigynia few, mostly 1-6, ascending, plump, ellipsoid, thick-walled, obscurely to conspicuously ribbed and sulcate, usually becoming rich, shining brown, 3-4 mm including the evident, hyaline beak; achene trigonous, filling the perigynium; rachilla more than half as long as the achene; 2n=52. Dry plains and hills; w. Ont., Minn. and Nebr. to Utah, Alas., and Eurasia. If the rachilla is wanting, see sp. 88.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.