Glumes a fourth to half as long as the spikelet, awnless or with an awn to 3 mm (first glume) or 5 mm (second glume); lemma with an awn 2-13(-18) mm, or seldom awnless; widespread, mostly in dry, sandy or rocky soil.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.