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, erect, smooth or very nearly so, 1°-2° tall, arising singly from elongated rootstocks. Leaves 1"-2 1/2" wide, roughish, the upper overtopping the spikes; bracts similar to the upper leaves, rough, strongly sheathing; staminate spike solitary, long-stalked; pistillate spikes 1-4, oblong, about 1' long, 8"-12" thick, erect, the lower slender-stalked, the upper nearly sessile; perigynia ovoid, much inflated, smooth, strongly several-ribbed, shining when mature, 5"-6" long, about 2 1/2" in diameter at the rounded base, contracted into the long 2-toothed beak, the small teeth slightly spreading; scales oblong-lanceolate, acute or acuminate, about one-half as long as the perigynia; stigmas 3.
Flor. 376. 187c. Carex lupulina Bella-villa Bailey, Mem. Torr. Club 1: 12.
1889. C. Bella-villa Dewey, Am. Journ. Sci. (II.) 41: 229. 1866.
Glabrous, culms stout, erect, 1°-4° tall. Leaves elongated, nodulose, 21/2"-8" wide, the upper ones and the similar bracts much overtopping the culm; staminate spike solitary, rarely several, nearly sessile or slender-peduncled, rather stout; pistillate spikes 2-5, densely many-flowered, sessile to long-stalked, oblong, 1-3' long, often 1' or more in diameter; perigynia ascending, much inflated, many-nerved, 5"-10" long, 2"-3 1/2" in diameter just above the base, contracted into a subulate 2-toothed beak; achene longer than thick, thickened but not knobbed on angles; scales lanceolate, acuminate or aristate, generally much shorter than perigynia; stigmas 3.
In swamps and ditches, New Brunswick to Hudson Bay, western Ontario, Iowa, Florida and Texas. June-Sept.
Carex lupulina var. polystachya Schw. & Torr. Ann. Lye.
1: 337. 1825. Not C. polystachya Sw. Carex lupuliformis Sartw.; Dewey, Am. Journ. Sci. (II.)
9: 29. 1850.
Glabrous, culm stout, erect, 1 1/2°-3° tall. Leaves and bracts similar to those of the preceding species, much elongated; staminate spike solitary, stalked or nearly sessile, sometimes 4' long; pistillate spikes 3-6, stalked or the upper nearly sessile, densely many-flowered, oblong-cylindric, 1 1/2-3 1/2" long, io"-I5" in diameter, often staminate at the top; perigynia yellowish brown at maturity, at first appressed, later ascending, sessile, much inflated, several-nerved, 5"-10" long, 2 1/2"-3 1/2" in diameter above the base, contracted into a subulate 2-toothed beak; achene often thicker than long, its angles strongly knobbed; scales lanceolate, awned, generally shorter than the perigynia.
Swamps, Vermont to Minnesota, south to Delaware and Louisiana. June-Sept.