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..
Carex Richardsonii R. Br. Frankl. Journ. 751. 1823.
Stolomferous, the culms slender, rough, erect, 4'-12' tall. Leaves flat, about 1" wide, the basal shorter than or sometimes equalling the culm, those of the culm very short; bracts bladeless, sheathing, -1/4'-1' long, usually brown-purple with a white hyaline acute summit; staminate spike solitary, stalked, 6"-13" long; pistillate spikes 1 or 2, erect, narrowly cylindric, short-stalked, 4"-10" long, compactly many-flowered, close together, their stalks partly or wholly enclosed in the sheaths; perigynia obovoid, triangular, pubescent, about 1" long, minutely beaked, obscurely nerved, mostly shorter than the ovate, subacute, purple, conspicuously white-margined scales; stigmas 3.
In dry soil, Ontario to Saskatchewan, Alberta and British Columbia, south to western New York, Illinois, Iowa and South Dakota. Summer.
Glabrous, pale green, culms filiform, smooth, weak, 4-15' long, from slender, elongated rootstocks. Leaves filiform, shorter than the culm, less than 1/4" wide; bracts reduced to bladeless sheaths 2"-5" long; staminate spike solitary, sessile or very nearly so, 2"-4" long; pistillate spikes 2-4, erect, slender-stalked, 2"-4" long, rather less than 1" thick, loosely few-flowered, the upper commonly overtopping the staminate, the lower one sometimes distant; perigynia oblong, pointed at both ends, 3-angled, 1" long, 1/2" or less thick, polished and nearly black when mature, very faintly few-nerved, tapering into a short entire beak; scales ovate, obtuse or the lower acute, thin, hyaline, shorter than the perigynia; stigmas 3.
In dry sandy or rocky soil, preferring limestone rocks, New Brunswick to Alberta, south to Virginia, Tennessee, Missouri and Nebraska. May-July.
Similar to the following species, the culms slender, usually 6"-2° long, from slender elongated rootstocks. Leaves flat, 1"-2" wide, generally shorter, than culm; bracts similar to culm-leaves, the lower exceeding spikes, sheathing, not dark auricled; terminal spike short-stalked, gynae-candrous or frequently staminate; pistillate spikes 2-5, linear-oblong, the upper aggregated and sessile or short-stalked, the lower distant and long-stalked, loosely or somewhat compactly 6-20-flowered, 2"-10" long, about 1 3/4 " thick; perigynia ellipsoid or narrowly obovoid, whitish pulverulent and not fleshy or translucent at maturity, less than 1" in diameter, the nerves faint, tapering at base, beakless, the orifice entire; scales as in the next, but more often dark-tinged; stigmas 2.
Labrador to north Maine, westward across the continent and south in the mountains of California. June-Aug.