Spikelets 3.5 mm or more to the base of the awn or mucronate tip of the sterile lemma; sterile lemma with an awn 6-25 mm, or seldom awnless. (E. pungens)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.