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 sedges, with leafy triangular culms (in a southern species the leaves reduced to inflated sheaths) and many-flowered terete spikelets in terminal and axillary clusters, or rarely solitary. Scales spirally imbricated all around, awned, the 1 or 2 lower commonly empty. Flowers perfect. Perianth of 3 ovate-oblong or cordate-ovate, stalked, often awned scales, usually alternating with as many downwardly barbed bristles. Stamens 3. Style 3-cleft, not swollen at the base, deciduous. Achene stalked or nearly sessile, sharply 3-angled, acute or mucronate, smooth. [In honor of George Fuiren, 1581-1628, Danish physician.]
About 30 species, natives of warm-temperate and tropical regions. Besides the following, 4 others occur in the southern United States. Type species: Fuirena umbellata Rottb.
Perianth-scales awned from the apex or awnless.
Annual: perianth-scales lonp-awned.
Perennial; perianth-scales short-awned or awnless.
F. hispid a.
Perianth-scales awned on the back below the apex.
Annual, with fibrous roots, the rootstocks very short or none; culms tufted, glabrous or nearly so, 2'-1° tall. Leaves flat, nearly or quite glabrous or the lower sheaths pubescent; spikelets sessile and 1-10 together in terminal and often also lateral capitate clusters, ovoid or ovoid-oblong, acute or obtuse, 3"-6" long, about 2 1/2" in diameter; scales ovate or oblong, brown, pubescent, mostly obtuse, 3-nerved, tipped with a stout spreading or recurved awn of nearly their own length; perianth-scales oblong to ovate, long-stalked, usually narrowed at both ends, tapering into a slender terminal downwardly barbed awn; bristles mostly longer than the achene.
Fuirena hispida Ell. Bot. S. C. & Ga. 1: 579. 1821. F. squarrosa hispida Chapm. Fl. S. States 514. 1860.
Perennial by short rootstocks which often bear tubers; culms glabrous or pubescent, 8'-2i° high. Leaves flat, both the blades and the sheaths more or less densely hirsute; spikelets 2-8 together in capitate terminal and usually also axillary clusters, similar to those of the preceding species, the scales with spreading or recurved awns; perianth-scales deltoid-ovate, cordate to rounded at the base, stalked, tipped with a short smooth awn or merely mucronate; bristles mostly downwardly barbed, shorter or longer than the achene.
Wet grounds, New York(?), New Jersey to Florida, Kentucky, Indian Territory and Texas. June-Oct.
Fuirena simplex Vahl, Enum. 2: 384. 1806.
Fuirena squarrosa var. aristulata Torr. Ann. Lye. N. Y. 3: 291. 1836.
Similar to the preceding species, rootstock short, thick; culms slender, 5'-2° tall, glabrous. Leaves flat, glabrous or ciliate; scales tipped with a spreading or reflexed awn; sepals ovate-oblong, obtuse and usually notched at the apex, obtuse, truncate or subcordate at the base, longer or shorter than their stalks, awned on the back from below the apex, the awn varying in length, smooth or downwardly barbed; bristles re-trorsely hispid, equalling or exceeding the sessile or short-stalked achene.
In moist soil, Nebraska, Missouri, Kansas, Texas and Mexico. Also in Cuba. June-Sept.