Plants not cespitose, long-rhizomatous. Culms 13-49 cm, triangular, scabrous distally. Leaves: basal sheaths reddish brown to dark brown; blades plane, 1.1-3.5 mm wide, equaling or exceeding culms. Spike with staminate portion separated from pistillate portion by short but conspicuous internode, with pistillate portion unbranched, 7.5-26.5 × 1.3-2.2 mm. Pistillate scales brown, chartaceous, apex cuspidate to short-awned. Staminate scales reddish brown, apex cuspidate to short-awned. Anthers 2.2-6.2 mm. Perigynia 1-3, greenish yellow to brown, with 2 marginal veins, otherwise veinless, 5-6.8(-8.4) × 1.8-2.8 mm. Fruiting late Apr-late Aug. Dry montane and subalpine grasslands, burns, and open spruce, fir, or pine woods; 800-3300 m; Alta., B.C.; Colo., Idaho, Mont., Nev., Oreg., Pa., Utah, Wash., Wyo. A disjunct population of Carex geyeri is known from Centre County, Pennsylvania, well beyond the normal range of the species in the western mountains. The site should be re-examined to determine whether it persists there and whether it was native or introduced. Carex geyeri is an important native forage species in western montane grasslands (A. Cronquist et al. 1972+, vol. 6).
Loosely cespitose, the aphyllopodic stems 1.5-5 dm tall from short rhizomes; lvs elongate, flat, 1.5-3 mm wide; spike 1, the terminal staminate part slender, 1-2.5 cm; pistillate scales oblong-obovate, longer and wider than the perigynia, acute or the lower short- cuspidate, with hyaline margins; perigynia 1-3, ellipsoid or obovoid, obscurely trigonous, 5-6 mm, 2- ribbed, otherwise nerveless, tapering to a spongy base, rather abruptly contracted above to the scarcely beaked tip; achene trigonous, 4-5 mm, filling with perigynium; rachilla to half as long as the achene, or obsolete. Dry woods in calcareous soil; Centre Co., Pa.; Alta. to Colo., w. to B.C. and Calif.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.