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..
Scirpus maritimus var. fluviatilis Torr. Ann. Lye. N. Y. 3:
324. 1836. Scirpus fluviatilis A. Gray. Man. 527. 1848.
Perennial by large rootstocks, culm stout, smooth, sharply triangular with nearly flat sides, 3°-6° tall. Leaves 4"-8" wide, smooth, equalling or overtopping the culm, attenuate to a very long tip, the midvein prominent; those of the involucre 3-5, erect or spreading, some of them 5'-10' long; spikelets in a terminal umbel, solitary, or 2-3 together at the ends of its long spreading or drooping rays, or the central spikelets sessile, oblong-cylindric, acute, 8"-12" long, about 3 1/2" in diameter; scales ovate, scarious, puberulent, the midvein excurrent into a curved awn 1 1/2"-2" long; bristles 6; rigid, downwardly barbed, about as long as the achene; style 3-cleft; achene sharply 3-angled, obovoid, rather dull, short-pointed, 2" long.
S". Fernaldi Bicknell, Torreya 1: 96. 1901.
Perennial; culms rather pale green, slender, sharply 3-angled, 2 1/20 tall or less. Leaves 1" - 3" wide, the upper equalling or surpassing the inflorescence, those of the involucre 3 or 4, the longest one 5' long or less; spikelets ovoid, 5"-8" long, sessile in a terminal cluster and solitary at the ends of the slender umbel-rays; scales finely puberulent, acuminate, entire or lacerate, the recurved awn 1 1/2"-6" long; bristles as long as the achene or shorter; style 3-cleft; achene obovoid-cuneate, about 1 1/2" long and thick, trigonous, with rounded angles, yellow-brown and shining.
Shore of Somes Sound, Mt. Desert, Maine. July-Aug.
Perennial by rootstocks; culm stout, erect, 4°-7° tall, sharply 3-angled, the sides flat or nearly so. Leaves long, 4"-6" wide, somewhat roughish on the margins when dry, the lowest reduced to pointed sheaths, those of the involucre 2-5, the longer of them much exceeding the inflorescence; spikelets narrowly cylindric, acute, 3/4-2' long, less than i' thick, solitary or 2-5 together at the ends of the rays of the umbel, the rays 1-4' long; scales awned; bristles 2-4, shorter than the grayish-white dull obovate achene, which is distinctly 3-angled; stamens 3; style 3-cleft.
In fresh water and brackish marshes, Massachusetts to New York.
Scirpus sylvaticus L. Sp. PI. 51. 1753.
Perennial by long rootstocks; culm triangular, stout, smooth, 4°-6° tall, often overtopped by the upper leaves. Leaves flat, 5"-8" wide, rough on the margins, more or less rugulose, the midvein prominent, those of the involucre 5-8, the larger similar to those of the culm, often 1° long or more; umbel terminal, very large, sometimes 8' broad, about 3 times compound, the spikelets ovoid or ovoid-oblong, mostly acute, 1 1/2-2 1/2 long, borne in capitate clusters of 2-8 at the ends of the raylets; bractlets of the involucels small, scarious, linear or lanceolate; scales ovate-oblong, obtuse, brown with a green centre; bristles 6, downwardly barbed, slightly exceeding the achene; stamens 3; style 3-cleft; achene oblong, 3-angled., obtuse, nearly white, mucronulate, not shining.
In swamps, Maine to Georgia and Michigan. Also in Europe and Asia. June-Aug.