Spikelets 2-fld, disarticulating above the glumes and between the lemmas; rachilla hairy, prolonged beyond the base of the upper lemma; glumes membranous, usually shining, equaling or longer than the lemmas; lemmas membranous, obtuse or often truncate and erose-toothed, rounded on the back, obscurely 5-veined, the midvein diverging at or below the middle into a short awn, the callus bearded; annuals or more often perennials with narrow lvs and conspicuous panicles of purplish to silvery or yellowish spikelets. 30+, temp. and cold regions.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.