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 tufted grasses, with thick linear leaf-blades having thickened white margins, and dense contracted almost capitate panicles. Spikelets several-many-flowered; empty basal scales 2, narrow, acuminate; flowering scales broad, 3-nerved, pubescent on the nerves below, and sometimes also on the body of the scale at the base, with long silky white hairs, the apex acuminate, entire or slightly 2-toothed, the awn terminal or arising between the minute teeth. Stamens 3. Styles short, distinct. [Greek, in reference to the hairy nerves of the flowering scale.]
Culms tufted, 2 1/2'-12' tall, smooth and glabrous, the sterile shoots 4' tall or less. Sheaths smooth, a tuft of hairs on each side at the apex, much shorter than the internodes; ligule a ring of short hairs; blades strict or curved, thick, linear, obtuse, 1-nervcdrthe margins white, serrulate, 1 1/2' long or less, less than 1" wide, folded, at least when dry, pubescent with long hairs, especially beneath; panicle almost racemose, long-exserted, 1/2'-1 1/2' long; spikelets 3-10, crowded, 8-12-flowered; empty scales acuminate, 1-nerved; flowering scales 3"-3 1/4" long, acuminate, 3-nerved, the midnerve generally excurrent in a short point, all the nerves (the lateral at the top and bottom, the midnerve below the middle), the callus, and the base pilose.
Dry soil, Kansas to Nevada and Mexico. April-Sept.