This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Culms 2°-3° tall, slender, erect; sheaths glabrous, rarely the lower pubescent; blades up to 8' long, 2"-4" wide, rough on the lower surface, appressed-pubescent on the upper surface; spike 2 1/2' -4' long, nodding, long-exserted; spikelets 2-flowered, in pairs, the empty scales subulate, indurated at the base, hispidulous, attenuate into a long awn; flowering scales glabrous or hispidulous, bearing a straight hispidulous awn 10"-20" long.
In woods and on banks, New Jersey and Staten Island to Iowa and Arkansas; also at Hot springs, South Dakota. July and Aug. Figured in our first edition as E. striatus Willd., from which it is now distinguished.
Elymus diversiglumis Scribn. & Ball, Bull. U. S. Dep. Agr. Agrost. 24: 48. f. 22. 1901.
Culms 2 1/2°-4° tall, stout, erect; sheaths glabrous; blades up to 10' long, 3"-6" wide, rough; spike 4'-6' long, flexuous; spikelets 2-flowered, in pairs, the empty scales subulate, variable in length, from a short awn-like body up to ¥ long or more, the flowering scales 4"-5" long, hispidulous and sparingly hirsute, the hispidulous awn 10"-15" long.
Wisconsin and Minnesota to North Dakota and Wyoming. July and Aug.