Densely tufted perennial 3-12 dm; lvs mostly below the middle of the stem, the blades flat or folded, 1-5 mm wide, ligules often elongate to 3-12 mm; infl loose and open to narrow and contracted, the lower branches in fascicles of 2-5; spikelets purplish or silvery, 2.3-5.7 mm, the first glume 2-5.1 mm, the second 2.7-5.3 mm, acute or obtuse and often erose-tipped; rachilla prolonged one-fourth to one-half the length of the upper floret; lemmas glabrous, usually truncate and 4- toothed, the awn attached below the middle, straight or nearly so, from shorter than to barely exceeding the lemma; palea bifid, anthers 1.3-2.3 mm; 2n=24-28, 52, 56. Wet or boggy ground; circumboreal, s. to N.J., W.Va., N.C., Ill., Minn., and Ariz. A complex sp., the vars. not yet well understood.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.