Carex filifolia Nutt.

Carex filifolia Nutt. Gen. 2: 204. 1818
Uncinia brrvisela Torr. Ann. Lye. N. Y. 3: 428. 1836. (Type from northwestern Canada.) Kobresia globularis Dewey, Am. Jom". Sci. 29: 253. pi. 7. f. 86. 1836. (Type from Carleton House.
Saskatche wan . ) Ololrema filifolia Raf. Good Book 25. 1840. (Based on Carex filifolia Nutt.) Itheta breviseta Raf. Good Book 28. 1840. (Based on Uncinia brevisela Torr.) Uncinia filifolia Xees, in Max. Reise N. Am. 2: 450. 1841. (Based on C.filifolia Nutt.)
Ver>' densely cespitose, the rootstocks very short, stout, blackish, fibrillose, the culms 8-30 cm. high, fUiform, wiry but stiff, about the length of or somewhat exceeding the leaves, obscurely triangular, smooth or nearly so, brownish at base, the old basal sheaths broad, loose, conspicuous, striate, and normally strongly filamentose, the blades usually broken off; leaves of the year with well-developed blades 2 or 3 to a culm, bunched near the base, the blades wirj-, acicular, involute, resembling the culms, 3-20 cm. long, and about 0.25 mm. wide, stiff, lightgreen, more or less roughened, the sheaths truncate at the mouth, the ligule very short; spike solitarj-, erect, linear, 1-3 cm. long, 3-5 mm. wide, the upper half staminate, the lower with about 5-15 erect-ascending perigynia; bracts none; staminate scales broadly obovate, obtuse, light-reddish-brown with broad and conspicuous white-hyaline margins; pistillate scales similar but broader, very obtuse but occasionally mucronulate, the bright-white-hyaline margins very broad and conspicuous, the scales longer and wider than and entirely concealing the perig>-nia until maturity, the whole scale sometimes largely white-hyaline; perigynia obovoid or obovoid-orbicular, 3-3.5 mm. long, 2 mm. wide, membranaceous, obtusely triangular, rounded on the angles, obscurely 2-ribbed, otherwise nerveless or nearly so, puberulent above, tightly enclosing the achene, dull-whitish or straw-colored, tinged with yellowishbrown, round-tapering at base, truncately narrowed into a minute beak about 0.2-0.4 mm. long, stoutish, truncately-cut, hyaline; achenes obovoid, triangular, with low-convex sides, 2.25-3 mm. long, tapering at base, apiculate; style thickish, obscurely jointed with achene and at length deciduous, black, exserted; stigmas three, slender, elongate, blackish; rachilla present, minutely serrate.
Type locality': "Hab. On the dry plains and gravelly hills of the Missouri." Distribution: Plains and ridges, Texas and New Mexico, northward to Washington, and in the interior to Yukon. (Specimens examined from Texas, New Mexico, Nebraska. South Dakota. North Dakota. Manitoba. Saskatchewan. Montana. Wyoming, Colorado, Idaho, Oregon, Washington, Yukon.)