Culms obtusely trigonous in cross section, 15-70 cm, smooth. Leaves: ligules 1.2-3 mm, wider than long; blades yellowish green, M-shaped to flat, widest leaves 1.6-3.5(-4.2) mm wide, smooth abaxially, minutely papillose adaxially, especially distally. Inflorescences 1.8-18 cm; bract sheaths with apex concave; proximal (1-)2-3(-4) spikes pistillate, distal spikes erect, aggregated or the proximal sometimes remote, ovoid. Pistillate scales narrowly ovate, mostly 1/3-2/3 length of perigynia, apex acute. Anthers 1.1-2.7 mm. Perigynia spreading or the proximal somewhat reflexed, yellowish green, 20-26-veined, essentially uninflated, lanceolate, 8.7-12.1 × 1.3-2.1 mm, 4-7 times as long as wide, apex tapered, bidentulate; beak absent. Achenes 2.2-3 × 1.2-1.7 mm. Fruiting late spring-summer. Bogs, fens, lakeshores, stream banks, open seeps, in sandy or peaty, often acidic soils; 0-1000 m; St. Pierre and Miquelon; Man., N.B., Nfld. and Labr., N.S., Ont., Que., Sask.; Maine, Md., Mass., Mich., Minn., N.H., N.Y., Vt., Wis. Carex michauxiana is closely related to the east Asian C. dolichocarpa C. A. Meyer ex V. I. Kreczetowicz.
Tufted, 2-6 dm; main lvs 1.5-4 mm wide; terminal spike staminate, 0.6-1.5 cm, sessile or nearly so, scarcely projecting beyond the upper pistillate ones; pistillate spikes 2-4,
broadly ovoid, 1.5-2.5 cm, erect, the lower distinctly peduncled, the upper less so; bracts lf-like, 1-3 mm wide, surpassing the stems, their sheaths concave at the mouth; pistillate scales ovate, a third to half as long as the perigynia, hyaline or brown-tinged, with green midstrip, acute or acuminate; perigynia slenderly subulate, 8-13 נ1.5-2 mm, nearly circular in cross-section, sharply many-nerved, long-attenuate into a slender beak with erect teeth 1 mm; achene loosely enveloped, rounded-trigonous, continuous with the persistent slender style. Bogs and wet meadows; Nf. to Ont., n. Mich., n. Wis., ne. Minn., and Sask., s. to N.Y.; e. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.