This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Glabrous, densely tufted, long-stoloniferous, culms slender, erect, sharply 3-angled, 3'-10' tall. Leaves 1/2'-3/4" wide, flat, shorter than the culm, roughened toward apex; lower bract short, subulate; staminate spike solitary, sessile or very nearly so, 3"-7" long; pistillate spikes 1-3, sessile, approximate, subglobose or short-oblong, usually 4-10-flowered, 2"~4" long, 2" wide, the upper one sometimes consisting of only 1-3 flowers; perigynia oval-obovoid, smooth, hard, shining, nerveless, 1 1/4"-1 3/4" long, less than 1/2" thick, obscurely 3-angled, tipped with a very short, obliquely cut beak; scales ovate, brownish with hyaline margins, obtuse to short-cuspidate, about length of perigynia; stigmas 3.
Northern Minnesota (according to Bailey) and Manitoba to arctic America and Greenland. Also in northern Europe and Asia. Summer.
Car ex rupestris All. Fl. Ped. 2: 264. pi. 92. f. 1. 1785.
Carex Drummondiana Dewey, Am. Journ. Sci. 29: 251. 1836.
Culms slender, obtusely 3-angled, erect, 1'-6' tall. Leaves 1/2"-1" wide, involute in drying, often curved, shorter than or exceeding the culm; bract wanting; spike solitary, androgynous, slender, 6"-12" long, the pistillate part loosely few-flowered; perigynia erect, smooth, oblong-obovoid, triangular, long-stipitate, firm, faintly nerved, 1 1/2"-2" long, abruptly very short-beaked, the beak truncate; scales purple-brown, ovate, obtuse or subacute, wider and longer than the perigynia; stigmas 3.
Quebec and Greenland to British Columbia, south in the Rocky Mountains to Colorado. Also in northern Europe and Asia. Summer.
Carex filifolia Nutt. Gen. 2: 204. 1818.
Densely tufted, pale green and glabrous, culms slender but wiry, smooth, erect, 3'-14' tall, equalling or longer than the leaves. Leaves filiform, rather stiff, scarcely i" wide, their sheaths persistent and ultimately fibrillose; spike solitary, erect, bractless, androgynous, 3"-15" long, the pistillate part about 2" in diameter; perigynia 5-10, ovoid-oval, obtusely triangular, nearly nerveless, closely enveloping achene, puberulent at least above middle, 1 1/2" long, rather more than i" thick, tipped by a short cylindric hyaline entire beak; scales very broad and enveloping perigynia, concave with wide white scarious margins, obtuse or cuspidate, about as long as the perigynia; stigmas 3.
In dry soil, Manitoba to British Columbia, south to Kansas, Colorado and California. May-July.
Carex scirpoidea Michx. Fl. Bor. Am. 2: 171. 1803.
Dioecious, foliage glabrous, rather bright green, culms from elongated rootstocks, aphyllopodic, erect, slender but stiff, 6'-18' tall. Leaves 1/2"-1" wide, nearly erect, usually much shorter than the culm; spike solitary or rarely with an additional and very small one near its base, linear-cylindric, densely many-flowered, 8"-15" long, 1 1/2"-2 1/2" in diameter, subtended by a short or sometimes subulate bract; perigynia numerous, oval, two-nerved, obscurely triangular, densely pubescent, 1 1/2" long, 1/2" thick, narnwed at the base, tipped with a very short entire or at length slightly bidentate beak; scales oblong-obovate, dark purple with a narrow green midvein, ciliate, obtusish, nearly as long as the perigynia.
In rocky soil, Greenland to Alaska, south to the higher mountains of New England, Lake Huron and British Columbia. Also in northern Europe. Summer.