Hordeum murinum L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Much like no. 6 [Hordeum leporinum Link]; floret of the central spikelet sessile or subsessile, the rachilla-joint not nearly as long as the pedicels of the lateral spikelets; lemmas of the lateral spikelets larger, 10–18 mm; 2n=14, 28, 42. Roadsides, ditch-banks, and waste places; native of Europe, intr. and well established in w. U.S., sporadic with us.