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..
Erect perennial grasses, with flat leaf-blades and spikelets of two kinds; one kind borne in terminal panicles, deciduous without perfecting fruit; the other solitary, terminating subterranean peduncles, and maturing seed. Scales 3, membranous, the innermost subtending a palet and a perfect flower; the scales of the subterranean spikelets become indurated and enclose the grain. Stamens 3. Stigmas plumose. [Greek, from the two kinds of spikelets.]
Culms erect, I2'-i8' tall, slender, glabrous. Sheaths papillose-hirsute; ligule pilose; blades 1'-6' long, 2"-6" wide, erect, acuminate, hirsute and ciliate; panicle linear, 4'-6' long, branches 3-4, erect, bearing few spikelets; spikelets about 2" long, elliptic; outer scales 5-nerved, membranous, glabrous; subterranean spikelets ovoid in fruit, about 3" long, acute, the scales all becoming much indurated.
In moist pine barrens, New Jersey; also in Florida (according to Chapman). Aug.-Sept.