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 slender but stiff, obtusely triangular, smooth below inflorescence, not filamentose at base, 6'-1 1/2° tall, caespitose but stoloniferous. Leaves 1 1/2" wide or less, strongly involute, usually exceeding the culm, not strongly nodulose, somewhat roughened towards apex, the lowest bract short, strongly exceeded by culm, usually widely divergent; staminate spikes 1-2, short-stalked; pistillate spikes 1-2, ascending, oblong, 5"-9" long, 4"-5" wide, sessile or very short-stalked; perigynia squarrose-spreading, dark-tinged, obsoletely nerved, broadly ovoid, inflated, 2-3" long, abruptly contracted into a short minutely 2-toothed beak; scales ovate, acute, narrower and shorter than perigynia, dark-tinged; stigmas 3.
Arctic America and Greenland. Also in northern Europe and Asia. July-Aug.
Carex compacta R. Br. in Ross' Voy. App. cxliii. 1819.
Not Krock. 1814. Carex membranacea Hook. Parry's 2d Voy. App. 406.
Similar to the last, short-stoloniferous, the culms caespitose, 6'-18' high. Leaves flat, not exceeding the culm, 1 1/2"-2 1/4" wide, the margin revolute; bracts short, the lower commonly longer than its spike, the upper subulate; staminate spikes 1-3, short-stalked; pistillate spikes 1-3 (commonly 2), sessile or the lower short-peduncled, approximate, narrowly oblong, densely 25-75-flowered, 6"-15" long, 4" in diameter; perigynia spreading, dark-tinged, broadly oval to obovoid, fragile, much inflated, about 2" long and 1" wide, tipped with a short minutely bidentate beak, little-nerved, rather longer than the ovate-oblong, brownish, hyaline-margined scales; stigmas usually 3.
Greenland and north Labrador to Alaska. Summer.
Glabrous, culms stout, erect, 1°-4° tall, thick at base, generally obtusely angled and smooth above. Leaves elongated, strongly nodulose, the upper mostly exceeding the culm, 1"-6" wide, the midvein prominent; bracts overtopping the culm; staminate spikes 2-4, linear, stalked, the lower occasionally pistillate at the top and usually subtended by a very slender bract; pistillate spikes mostly 2 to 4, nearly erect, cylindric, densely many-flowered, the perigynia in many rows, or sometimes looser near the base, 2'-6' long, 3"-10" thick, the lower short-stalked, the upper sessile, sometimes staminate at the summit; perigynia spreading when old, ovoid, light green, somewhat inflated, few-nerved, 2"-4" long, abruptly contracted into a short 2-toothed beak; scales lanceolate, the lower awned and slightly longer than the perigynia, the upper acute; stigmas 3.
Marshes, Labrador to British Columbia, Delaware, Ohio and California. Also in Europe and Asia. June-Sept.