Tufted perennial 1-5 dm, decumbent at base; lvs 1-4 mm wide, flat, often becoming involute; ligules mostly under 2 mm; infl ovoid, 6-20 cm, loosely branched, its branches and pedicels scabrous, the lower branches spreading or reflexed, usually bearing spikelets only beyond the middle; spikelets 3-5 mm, 3-7-fld; glumes ovate, the first 0.7-1.8 mm, the second 1.2-2 mm; lemmas elliptic to obovate, obscurely veined, glabrous or short-pilose at base, scabrous on the margins toward the broadly obtuse to truncate tip; first lemma 1.7-2.5 mm; anthers 0.7-1.1 mm; 2n=14, 28, 42. Native of Europe, naturalized along the coast from N.B. to Del., and becoming common inland especially along highways in our range, w. to the Pacific.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.