Prairie Sedge

The geographic range of Carex prairea is rather fragmented except for a core zone that extends from southern Quebec and New England to Alberta. Oregon, Idaho, Wyoming, and California reports should probably be referred to C. cusickii or some other species, because south of the Canadian border (except for one locality in western Montana), C. prairea is unknown from west of the Great Plains. Carex appropinquata Schumacher, reported from Manitoba by W. J. Hooker ([1829–]1840, as C. paradoxa Willdenow) and from Colorado by L. Kelso (1953, 1953b), must be excluded. Hooker’s citation possibly refers to C. praegracilis W. Boott or less likely to C. prairea, and Kelso’s specimens (in US) are C. praegracilis.

Carex prairea and C. diandra are closely related and may not appear to be sharply differentiated. However, they maintain separate identities throughout their overlapping ranges and prefer subtly different habitats. Carex prairea is strictly calcicolous, avoiding saline groundwater and oligotrophic muskegs, whereas C. diandra does not require calcareous conditions and so is more likely to be found, for example, in New England and the Canadian Shield region.

Culms 3–6 cm (fl), elongating to 6–100 cm (fr). Leaves: sheaths adaxially strongly copper colored distally, truncate to convex at mouth, prolonged 2–8 mm beyond base of blade; ligules 1.2–5.8(–9.2) mm; foliage leaf blades 6–50 cm × 2–3 mm. Inflorescences bisexual or, sometimes, nearly or wholly unisexual, flexuous and interrupted, proximal 1–5 branches often separated, decompound, 3–8(–9) × (0.4–)0.8–1.8 cm; basal branch with (2–)4–10 spikes; proximal internode 7–26(–33) mm. Pistillate scales light reddish brown, 2.4–3.3 × (1.1–)1.4–2.1 mm, as wide as or wider than perigynia. Perigynia appressed or ascending, straw colored to light or dark brown, strongly 6–9-veined abaxially, with or without median lengthwise groove near base, sometimes membranous flap toward apex, lance-ovate (body ovate to very widely ovate) in outline, plano-convex, (2.1–)2.3–3(–3.3) × (1–)1.1–1.4 mm, dull; beak 0.8–1.4 mm. Achenes broadly or very broadly trullate-ovate in outline, 1.2–1.6 × 0.7–1 mm. 2n = 66.

Alta., B.C., Man., N.B., N.W.T., N.S., Ont., Que., Sask., Yukon; Conn., Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., Nebr., N.J., N.Y., N.Dak., Ohio, Pa., S.Dak., Vt., Va., W.Va., Wis.

Fruiting Jun–Jul (Aug in w Canada).

Wet meadows, peaty ground, usually in calcareous marshes, prairies, fens, and swales, often on borders of lakes and streams or in open conifer swamps (Larix, Picea, Thuja), also thickets and ditches; 0–1400m.

Carex diandra Schrank var. ramosa (Boott) Fernald

Carex prairea Dewey, in Wood, Class Book lit (as c. prarisa) 1845; ed. 2. .578 (us C. prairea). 1847.
■inuulala I. " Mill. I IB 224. 1817.
;.ir/j./..«« Wiiid " i;o.,it. inHool ii Boi Am. 2: 213, I paniculala var mm** Carey, in A Gray, Man 540. IH4H. (Baaed on C. prairea Dcwcy.)
pant' ulala var. minor RetZ, 177V. "Carex teretiuscula var. major Koch" Carey, in A. Gray, Man. ed. 2. 511. 1856.
Carex teretiuscula var. ramosa Boott, 111. Carex 145. 1867. (Based on C. prairea Dewey.)
Carex teretiuscula var. prairea Britton ; Britt. & Brown, 111. Fl. 1 : 344. 1896. (Based on C. prairea
Dewey.) Carex diandra var. prairea "Britton" Kiikenth. in Engler, Pflanzenreich 4-°: 177. 1909. (Based
on C. prairea Dewey.)
In large dense clumps, the rootstocks very short-elongate, rather slender, tough, blackish, fibrillose, the culms slender, 5-10 dm. high, 3 mm. thick at base, aphyllopodic, sharply triangular with flat sides, very rough on angles, much exceeding leaves, brown or dark-brown at base; leaves with well-developed blades usually 3 or 4 to a fertile culm, on lower fourth, somewhat bunched, the blades light-green, flat with revolute margins, usually 1-3 dm. long, 2-3 mm. wide, much roughened, the sheaths tight, thin and conspicuously red-dotted ventrally, conspicuously prolonged at mouth beyond base of blade, convex and strongly copper-tinged at mouth, the ligule very short; head somewhat decompound, 4-8 cm. long, 1-2 cm. thick, the lower 3-5 branches separated, the upper aggregated, the individual spikes closely aggregated, androgynous, ovoid, 3-6 mm. long, 2.5-4 mm. wide, the staminate flowers inconspicuous, the perigynia 5-10, appressed or ascending, in several rows; lowest bract setaceous, short, the others scale-like; scales narrowly ovate-triangular, acute or short-acuminate or cuspidate, light-reddish-brown, with light-colored 1-3-nerved center, and conspicuous hyaline margins, about as wide as or wider than and nearly as long as and concealing perigynia, often falling with it; perigynia plano-convex or slightly unequally biconvex, 2.5-3 mm. long, 1.25 mm. wide, dark-straw-colored or brownish, dull, the body ovate, thick, sharp-edged to base and serrulate above middle, few-nerved dorsally, obscurely few-nerved towards base ventrally, thick-walled, short-stipitate, truncate at base, tapering into a strongly serrulate beak of somewhat less than its own length, green or in age whitish, obliquely cut dorsally, shallowly bidentate, reddish-tipped with suture hyaline-margined; achenes lenticular, stipitate, apiculate, filling perigynia, suborbicular, scarcely 1 mm. wide; style very short, straight, slender, slightly enlarged at base, jointed with achene; stigmas two, slender, reddishbrown, shorter than to about equaling perigynium.
Type locality: "Abundant in the prairies of Michigan and sparingly found in N. England and N. Y."
Distribution: Wet meadows in calcareous districts. Quebec to Saskatchewan, and southward td New Jersey, Indiana. Iowa, and Nebraska. (Specimens examined from Quebec. Ontario, Vermont, Massachusetts, Connecticut, New York, New Jersey, Pennsylvania, Ohio, Indiana, Michigan, Wisconsin. Illinois, Minnesota. Iowa. Manitoba, North Dakota, Nebraska, Saskatchewan.)

Carex prairea, common name prairie sedge, is a species of Carex native to North America. It is a perennial.