Culms slender to stout, erect from a decumbent (even shortly stoloneous) base, 5-10 dm, without rhizomes, smooth or often scaberulous below the infl; sheaths finely scabrous; blades soft, 2-6 mm wide, the cauline ones often 15 cm; ligule (2.5-)3-7+ mm, panicle soon long-exsert, ovoid or oblong, the ascending branches in sets of 5-8, with numerous crowded spikelets; pedicels scabrous; spikelets ovate or elliptic, 2-fld and 2.7-3.2 mm or 3-fld and 3-4 mm; glumes lanceolate, incurved, the first 1.7-2.9 mm, the second 2-3.3 mm; lemmas thin, narrowly ovate, sharply 5-veined, acute or acuminate, glabrous except the scaberulous keel and webbed base; anthers 1-2 mm; 2n=14, 28. Native of Europe, intr. in meadows, moist woods, and along roadsides from Nf. to Minn. and S.D., s. to N.C. and Ill., and in the Pacific states.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.