Bromus japonicus Thunb.
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. 16 [Bromus commutatus Schrad.], and apparently passing into it, but the panicle avg a little larger, and with slender, flexuous, spreading to drooping branches; spikelets (13–) 15–30 mm; lemmas (6–)7.5–9 mm, 1.2–2.2 mm wide in side view; awns 7–12 mm, flexuous or recurved-divergent, the longest ones of a spikelet more than twice as long as that of the lowest lemma; palea 1–2.5 mm shorter than the lemma; 2n=14. Native of the Old World, intr. as a weed in waste places from N.H. and Vt. to Ga., w. to the Pacific.