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..
Fig. 912
Carex curta var. brunnescens Pers. Syn. 2: 539. 1807. C. brunnescens Poir. in Lam. Encycl. Suppl. 3: 286. 1813. Carex canescens var. vulgaris Bailey, Bot. Gaz. 13: 86. 1888. Carex brunnescens gracilior Britton; Brit. & Br. 111. Fl. 1: 351. 1896.
Rather dark green, not glaucous, culms slender, stiff, erect, roughish above, 8'-18' tall. Leaves 1/2"-1 1/4" wide, shorter than the culm; lower bract usually present, bristle-form; spikes 4-8, gynaecandrous, subglobose or short-oblong, 4-10-flowered, 2"-6i" long, somewhat scattered, or approximate; perigynia loosely spreading, brown-tinged, usually smaller than those of the preceding species, tipped with a manifest, minutely biden-tate, roughish beak about one-fourth as long as the body; scales ovate, membranous, brownish, somewhat shorter than the perigynia; stigmas 2.
In wet or even dry places, mostly at high altitudes, Labrador to British Columbia, New York and New England, on the southern Alleghanies, and the Rocky Mountains. Also in Europe. Ascends to 6600 ft. in North Carolina. Summer.

Fig. 913
Carex canescens var. polystachya Boott; Richards. Arct.
Exp. 2: 344. 1852. Not C. polystachya Sw. 1803. Carex arcta Boott, 111. 155. pl. 497. 1867.
Rather light green but scarcely glaucous, culms caespitose, slender, usually strictly erect, 6'-2 1/2° tall, rough above, often overtopped by the leaves which are flat and 1"-2" wide. Lower bract bristle-form and longer than its spike, or short, or wanting; spikes 5-15, oblong, or ovoid, many-flowered, gynaecandrous. 2"-5" long, 2"-3" in diameter, all aggregated into an oblong or ovoid head 7"-15" long; perigynia pale, ovate, broadest near base, many-nerved, ascending or somewhat spreading, i"-i 1/2" long, white-puncticulate, tapering into a serrulate bidentate beak about one-half as long as the body; scales membranous, usually pale brown, obtusish to short-cuspidate, shorter than the perigynia; stigm;
In swamns and wet woods, Maine and New Brunswick to British Columbia, south to Massachusetts, New York, Minnesota and California. June-Jury.

Fig. 914
Car ex Deweyana Schwein. Ann. Lye. N. Y. 1: 65. 1824.
Pale green, culms densely caespitose, slender, spreading, slightly angled above, 6'-3° long. Leaves 1"-2 1/2" wide, flat, soft, shorter than the culm; bracts bristle-form, the lower commonly elongated; spikes 2-7, gynaecandrous, ovate-oblong or subglo-bose, 3-15-flowered, about 2, 1/2" in diameter, sessile, distinctly separated or the upper ones contiguous; perigynia lanceolate or ovate-lanceolate, nerveless or nearly so, corky at base, 2"-2 1/2" long, sharply margined above, 3/4" wide, the inner face flat, the tapering rough strongly 2-toothed beak about one-half as long as the body; scales nearly white, hyaline with a green midvein, cuspidate or acuminate, equalling the perigynia, or shorter; achenes 1" long; stigmas 2.
In dry woods, Nova Scotia to British Columbia and Vancouver, south to Pennsylvania, Iowa, New Mexico and Arizona. May-July.

 
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