Carex backii Boott

Culms 1.4–25 cm. Leaves: basal sheaths pale to medium brown; blades dull green to yellowish green, longer than stems, 1.3–5.4 mm wide, coriaceous, margins green, crenulate to scabrous. Lateral spikes 0–3, basal, on erect peduncles. Terminal spikes with staminate portion 2–3-flowered, 2-–3.6 × 0.4–1 mm; pistillate portion 2–7-flowered. Pistillate scales green, margins (2–)2.5–6.5 mm wide, essentially concealing perigynia, apex acute, distal scales lanceolate to ovate, apex acute. Staminate scales green to pale brown, ovate to oblong, 1.9–3.5 × 0.8–1.5 mm, margins enfolding scales above, white, often with reddish brown tinge, apex obtuse. Anthers 0.9–1.3 mm. Perigynia dull green to dark olive green, ellipsoid to ovoid, 4.8–6.6 × 1.9–3.2 mm, loosely enveloping achenes, apex gradually tapering; beak 1.9–2.9 mm, smooth. Stigmas clavate, erect, shorth, thick, minutely papillose. Achenes 2.5–3.2 × 1.6–2.3 mm. 2n = 66.

Alta., B.C., Man., N.B., Ont., Que., Sask.; Colo., Maine, Mich., Minn., Mont., N.H., N.J., N.Y., N.Dak., Pa., S.Dak., Vt., Wis., Wyo.

Fruiting spring–summer (late May–late Jul).

Dry, rocky, open, or shaded slopes, ridges, and barrens, in hardwood, mixed, or coniferous forests, including pine plantations, on acidic and calcareous substrates; 200–2100m.

Carex durifolia L. H. Bailey

Carex backii Boott, in Hook. Fl. Bor. Am. 2: 210. pi. 209. 1839
Carex durijolia L. H. Bailey. Bull. Torrey Club 20: 428. 1893. (Based on C. Backii Boott.)
Cespitose, the rootstocks very short, dark-brown, the culms slender, weak, strongly triangular above, narrowly winged and serrulate on the angles, enlarged upward below spikes, from ver short to 25 cm. high, two to four times exceeded by the leaves, brown at base and with 2 or 3 bladeless or short-bladed leaves of the previous year; leaves with well-developed blades 2-6 to a culm, clustered near the base, the blades flat, erect to curved, 1-3 dm. long, 2.5-6 mm. wide, deep-green, thickish, minutely papillate, roughened especially on the margins and towards the apex, the sheaths very thin and hyaline ventrally, lightly yellowish-browntinged, oblique at mouth, the ligule wider than long; spikes androg>'nous, 1-3, usually 2, widely separated, the lower nearly basal and long-peduncled, the staminate part sessile or very short-peduncled, inconspicuous, 0.5-1 mm. wide, few(about 3-) flowered, the scales very closely appressed, oblong-obovate, obtuse to cuspidate, white with green center and tawny tip, the margins connate to above middle, the pistillate part with 2-5 erect perigynia on a zigzag, triangular, winged rachis, each subtended by a bract-like, leaf-like, many-nerved, long-tapering scale exceeding the perigynium, the lower scales about 3-4 cm. long and 5 mm. wide and hiding the perigj'nia, the upper gradually smaller; pcrig>'nia oblong-ovoid, 5-6 mm. long, the body oblong-orbicular, 3 mm. long, 2.5 mm. wide, glabrous, membranaceous, light-green, substipitate, contracted into a broad spongy base, 2-keeled and slenderly but faintly many-nerved, the upper third empty and tapering into a beak about 2 mm. long, stout, smooth, 2-edged, the margins decurrent on the body, the orifice entire, truncate, hyaline, and slightly tawnytinged below; achenes triangular-globose, with strongly convex sides, closely enveloped, yellowish-green when young, blackish at maturity, granular, constricted at base into a thick stipe, rounded and minutely umbonate at apex; style slender, jointed with achene, deciduous; stigmas three, rather slender, dark-colored, short.
Type locality: "Carleton House. Lake Winnipeg. Dr. Richardson. Rocky Mouutains. Drummond." The Richardson specimen is the type.
Distribution: Dry woods, Quebec to Massachusetts and northern New York, and westward to Alberta and eastern British Columbia. (Specimens examined from Quebec. Maine, Vermont, Massachusetts. New York. Ontario. Michigan, Wisconsin, Minnesota, Manitoba, Saskatchewan, Alberta, British Columbia.)

Carex backii, commonly known as Back's sedge, is a species of sedge (Carex) in the section Phyllostachyae. First described scientifically in 1839 by American botanist Francis Boott, it is found in Canada and the United States, where it grows in shaded woods, shaded slopes, and shrub thickets.