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..
Cyperus microdontus Torr. Ann. Lye. N. Y. 3: 255. 1836.
Annual, similar to the preceding species, culms very slender, tufted, sometimes 20' high, usually lower. Leaves about 1" wide, those of the involucre much elongated; umbel commonly simple, sessile, capitate, or 1-6-rayed; spikelets linear, acute, 3"-9" long, less than 1" wide, yellowish-brown; scales ovate, acute, brownish, thin, appressed when young, spreading at maturity; stamens 2; style 2-cleft, its branches much exserted; achene lenticular, linear-oblong, short-pointed, light brown, one-half as long as the scale, its superficial cells quadrate.
In wet soil, on or near the coast, New Jersey to Florida and Texas. Aug.-Oct.
Annual; bright green; culms tufted, slender, 5 dm. high or less, bluntly 3-angled. Leaves mostly shorter than the culm, 2" wide or less, sometimes very narrow, those of the involucre 3-5, usually much elongated; umbel 2-8-rayed, the rays often 2' long; spikelets linear or linear-lanceolate, 3"-7 1/2" long, about 1" wide, greenish-yellow; scales acute, oblong to oblong-lanceolate; achene oblong, 1/2" long, about one-half as long as the scale, its superficial cells quadrate.
Moist soil, Virginia to Florida, Arkansas and Texas. Also in tropical America. Aug.-Oct.
10. 1842. Cyperus sabulosus Mart. & Schrad.; Boeckl. Linnaea 35:
Annual, culms stout or slender, 1°-3° tall, leafy below. Leaves smooth, or rough-margined, 2 "-3" wide, those of the involucre 3-8, the longer ones much exceeding the inflorescence; umbels few-several-rayed, often compound; primary rays 1/2'-2 1/2' long; spikelets numerous, usually densely clustered, linear, acute, 4"-10" long, 1"-1 1/2" wide, flat, many-flowered, spreading; scales oblong, obtuse, thin, dull, yellowish-brown, scarious-margined, faintly 3-nerved; stamens 3; style 2-cleft, little exserted; achenes obovate, lenticular, black, mucronate, not shining, nearly as long as the scales and often persistent on the rachis after these have fallen away.
In wet or moist sandy soil, Virginia to Florida and Louisiana. Also in Brazil. Aug.-Oct.
Cyperus inflexus Muhl. Gram. 16. 1817.
Annual, culms slender or almost filiform, tufted, 1'-6' tall, about equalled by the leaves. Leaves 1" wide or less, those of the involucre 2-3, exceeding the umbel; umbel sessile, capitate, or 1-3-rayed; spikelets linear-oblong, 6-10-flowered, 2" - 3" long; scales light brown, lanceolate, rather firm, strongly several-nerved, tapering into a long, recurved awn, falling from the rachis at maturity; stamen 1; style 3-cleft; rachis narrowly winged, the wings persistent; achene 3-angled, brown, dull, narrowly obovoid or oblong, obtuse, mucronulate.
In wet, sandy soil, New Brunswick to the Northwest Territory and British Columbia, south to Florida, Texas, California and Mexico. Fragrant in drying. July-Sept.