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..
C. lancastriensis Porter; A. Gray, Man. Ed. 5, 555- 1867.
Perennial by ovoid or oblong corms, culm slender, smooth, mostly longer than the leaves, 1°-2 1/2° tall. Leaves 2"-3" wide, those of the involucre 4-7, the longer much exceeding the inflorescence; umbel simple, 5-9-rayed, the longer rays 2'-4' long, their sheaths nearly truncate; heads oval, obtuse, 1/2'-1' long; spikelets densely clustered, 4"-5" long, linear, subterete, 2-4-flowered, the lower reflexed, the middle ones spreading, all separating from the axis at maturity; scales green, strongly several-nerved, the flowering ones lanceolate, subacute; stamens 3; style 3-cleft; achene linear, obtuse, apiculate, 2-3 times as long as thick, two-thirds as long as the scale.
Cyperus hystricinus Fernald, Rhodora 8: 127. 1906.
Perennial by corms and rootstocks; culms rather stout, smooth throughout, 30 tall or less. Leaves smooth, 1"-2," wide, the basal ones shorter than the culm, those of the involucre about as long as the umbel; rays 14 or fewer, the longer 7' long or less; heads obovoid, or obovoid-cylindric, 1/2-1 1/2 long; spikelets yellowish-brown, subulate, 2"-4" long, the uppermost spreading, all the others strongly reflexed, bearing 1 or 2 achenes; fertile scales strongly nerved; stamens 3; achene linear, trigonous, about It" long, 3-4 times as long as the scale.
Dry sandy soil, New Jersey and eastern Pennsylvania to Georgia and Texas. Except for the smooth culm and leaves closely resembling C. retrofractus. July-Sept.
Not Boeckl. 1859. C. Torreyi Britton, Bull. Torr. Club 13: 215. 1886.
Perennial by small hard corms, culms slender, smooth, usually tufted, 4'-18'tall, longer than the leaves. Leaves smooth, \"-\\" wide, the longer ones of the involucre much exceeding the umbel; umbel simple, several-rayed, the rays short, or the longer \'-2\' long, the sheaths 2-toothed; heads very dense, cylindric, 1/4'- 1/2 long, 2"-4" in diameter; spikelets 1 1/2"-2" long, flattish, 1-2-flowered, spreading or the lower reflexed; scales green, oblong; rachis winged; stamens 3; style 3-cleft; achene linear-oblong, 3-angled, apiculate, slightly more than one-half as long as the scale.
In sandy pine barrens and on the sea shore, southern New York to Florida, west to Missouri and Texas. July-Sept.
Kyllingia ovularis Michx. Fl. Bor. Am. I: 29. 1803. Cyperus ovularis Torr. Ann. Lye. N. Y. 3: 278. 1836.
Perennial by hard tuber-like corms, culms usually strict, smooth, 8'-2 1/2° tall, longer than the leaves. Leaves smooth, 2"-3" wide, the longer ones of the involucre exceeding the umbel; umbel mostly simple, few-rayed, the rays rarely more than 2 1/2' long; sheath of the rays truncate or slightly toothed; heads globose or sometimes a little longer than thick, 4"-7" in diameter, very dense, the spikelets radiating in all directions; spikelets 2"-3 1/2" long, usually 3-flowered, separating from the axis and leaving a scar at maturity; rachis winged; scales ovate or ovate-lanceolate, obtuse or subacute, green, strongly several-nerved; stamens 3; style 3-cleft; achene linear-oblong, 3-angled, 2-3 times as long as thick.