Carex obtusata Lilj.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - 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.