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..
Culms low, tufted, erect or slightly curving, 2 1/2' or less tall, smooth, from slender rootstocks. Leaves 1" wide or less, involute toward apex, about equalling the culm; bracts usually absent; spike solitary (or rarely with a very small second one at base), brown, obovoid or suborbicular, 2"-3 1/2" long, 2" wide, gynae-candrous, but slightly clavate at base; perigynia 7-15, appressed, ovate, not margined or serrulate, 1" long, a little more than 1/2" wide, rounded and stipitate at base, light colored, weakly nerved, abruptly tipped with a very minute beak; scales ovate, strongly brownish-tinged, obtuse, slightly shorter than perigynia; achene filling perigynium; stigmas 2.
Culms stiff, erect, smooth, except immediately beneath head, 3'-16' tall, from slender rootstocks. Leaves flat, not involute, 1/2"-1 1/2" wide, shorter than the culm, bracts very short or wanting; spikes 2-6, gynaecandrous, oblong, dark brown, narrowed at the base, 2 1/2"-5" long, 1 1/2"-2 1/2" thick, densely many-flowered, clustered at the summit or the lower somewhat separated; perigynia appressed-ascending, elliptic or obovate, 1"-1 3/4" long, firm, lightly several-nerved, narrowed at the base, rather abruptly tipped by the beak; scales ovate, brown, hyaline-margined, obtuse to acutish, shorter than the perigynia; achene filling perigynium; stigmas 2.
Circumboreal. extending south to Quebec and Labrador and in the western mountains to Colorado and California. Summer.
Resembling Carex glareosa and Carex Lachenalii. Culms weak and slender, 2'-18' tall, smooth, except immediately beneath head, from slender rootstocks. Leaves narrow, 1/4"-3/4" wide, involute; spikes 2-8, gynaecandrous, oblong or subglobose, 2 1/2"-6" long, 1 1/2"-2" wide, brown, subtended by very small scale-like bracts; perigynia 5-10, broadly elliptic, 1 1/4" long, 3/4" wide, strongly several-nerved, pale or brownish at maturity; scales ovate, obtusish, brown with hyaline margins; achene filling perigynium; stigmas 2.
Circumboreal, extending south along the coast to Labrador and Quebec. Summer. Erroneously illustrated in our first edition as Carex glareosa Wahl.