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..
Perennial by slender rootstocks, culms tufted, smooth, slender, erect, somewhat compressed, 3'-15' tall. Leaves half-terete, smooth, shorter than the culm, channeled, ¥-3' long, less than 1' wide, the lowest reduced to bladeless sheaths; spikelets red-brown, few-flowered, narrowly ovoid-oblong, subacute, about 3" long, erect in a terminal 2-ranked spike 1/2'-l' long; involucral leaf solitary, erect, narrowly linear, equalling or longer than the spike; scales lanceolate, acute, 1-nerved; bristles 3-6, upwardly barbed, shorter than the achene, deciduous; stamens 3; style 2-cleft; achene oblong, pointed at both ends, light brown, plano-convex or slightly angled in front, I 1/2"-2" long.
In marshes, Newfoundland, New Brunswick, Nova Scotia and Quebec to James' Bay; Northwest Territory. Also in northern Europe. Summer.
Perennial by slender rootstocks, culm slender, smooth, sharply triangular, 1°-2° tall. Leaves usually pale green, smooth, shorter than or overtopping the culm, 1 "-2" wide, those of the involucre 2 or 3, the longer much exceeding the inflorescence; spikelets" 3-10 in a dense terminal simple head, oblong-cylindric, mostly acute, 8"-12" long, 2 1/2"-4" in diameter; scales ovate, membranous, puberulent or glabrous, pale to brown, 2-toothed at the apex, the midvein excurrent into an ascending or spreading awn about 1" long; bristles 1-3, much shorter than the achene or none; style 2-cleft; achene lenticular, obovate or oblong-ovate, mucronulate, yellow-brown.
Salt marshes, Quebec to New Jersey, about salt springs inland and on wet prairies and plains, Manitoba and Minnesota to Oregon, Nebraska, Kansas, Nevada and Mexico. May-Aug.
Perennial by large rootstocks, culm stout, stiff, sharply 3-angled with flat sides, smooth, 2°-5° tall. Leaves equalling or overtopping the culm, dark green, smooth, 2 1/2"-5" wide, the midvein prominent; involu-cral leaves 2-4, elongated, erect, similar to those of the culm, often I long; spikelets ovoid-oblong, obtuse or subacute, stout, 8"-12" long, 4"-5" in diameter, 6-20 together in a dense often compound terminal cluster; scales ovate, brown, puberulent, thin, lacerate or 2-toothed at the apex, the midvein excurrent into an, at length, reflexed awn, 1 1/2"-2 1/2" long; bristles 1-6, fragile, snorter than the achene or none; stamens 3; style 3-cleft; achene compressed, very flat on the face, convex or with low ridge on the back, obovate-orbic-ular, dark brown, shining, 1 1/2" long.
In salt marshes, Nova Scotia to Texas. Spurt-grass. Sea Club-rush. July-Oct.