Much like no. 3 [Bromus inermis Leyss.]; nodes long-hairy; sheaths glabrous or hairy; lvs 5–8 mm wide, hairy above, commonly glabrous beneath; auricles sometimes well developed; ligule 1–2.5 mm; infl 6–15 cm, narrow, with 1–4 ascending branches from a node; glumes glabrous; lemmas 5-or 7-veined, evidently hairy at least at the base and margins, the awn 1.5–4(–5) mm; 2n=42, 56. Native to w. U.S. and Can., disjunct in n. Mich. and s. Ont. Hybridizes readily with no. 3, and perhaps better called B. inermis ssp. pumpellianus (Scribn.) Wagnon, or var. purpurascens (Hook.) Wagnon.