Plants perennial; not rhizomatous. Culms 80-150 cm, erect; nodes 9-20, glabrous, usually concealed by the leaf-sheaths; internodes usually glabrous, sometimes hairy just below the nodes. Sheaths overlapping, densely to moderately retrorsely pilose or glabrous over most of their surface, throats and collars densely pilose; auricles 1-2.5 mm on most lower leaves; ligules 0.8-1.4 mm, hirsute, ciliate, truncate, erose; blades 20-30 cm long, 5-15 mm wide, flat, usually glabrous, rarely pilose, with 2 prominent flanges at the collar. Panicles 10-22 cm, open, nodding; branches spreading to ascending. Spikelets 15-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with 4-9 florets. Glumes pubescent or glabrous; lower glumes 4-7.5 mm, 1 (3) -veined; upper glumes 6-9 mm, 3-veined, sometimes mucronate; lemmas 8-14 mm, elliptic to lanceolate, rounded over the midvein, backs glabrous or pilose to pubescent, margins long-pilose, apices obtuse to acute, entire; awns 3-4.5 (7) mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2-3 mm. 2n = 14.
Conn., N.J., N.Y., Del., D.C., Wis., W.Va., Kans., N.Dak., Nebr., S.Dak., N.H., N.C., Pa., Alta., B.C., Man., N.B., Ont., Que., Sask., Va., Vt., Ill., Ind., Iowa, Maine, Md., Mass., Ohio, Mo., Minn., Mich., Mont., Tenn., Ky.
Bromus latiglumis grows in shaded or open woods, along stream banks, and on alluvial plains and slopes. Its range is mainly in the north-central and northeastern United States and adjacent Canadian provinces. Specimens with decumbent, weak, sprawling culms, densely hairy sheaths, and heavy panicles can be called Bromus latiglumis i. incanus (Shear) Fernald.
"decumbent" is not a number.