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..
Bromus inermis Leyss. FI. Hal. 16. 1761.
Culms tufted, 2 1/2°-3 1/2° tall. Sheaths smooth and glabrous; blades 6'-10' long, 2"-3' wide, smooth and glabrous; panicle 6'-10' long, oblong, the axis his-pidulous, the hispidulous branches ascending in clusters; spikelets 10"-12 1/2" long, about 2 1/2" wide, oblong, erect, the first scale 1-nerved, the second 3-nerved, the flowering scales 5"-6" long, 5-7-nerved, awnless or rarely awn-pointed.
In fields and waste places. South Dakota, Ohio and Colorado. Introduced from Europe. June and July.
Bromus Kalmii var. Porteri Coulter, Man. Bot. Rocky
Mt. Region 425. 1885. Bromus Porteri Nash, Bull. Torn Club 22: 512. 1895.
Culms 1 1/2°-3° tall, erect, simple, pubescent below the nodes. Sheaths shorter than the internodes, glabrous or sometimes softly pubescent; ligule 1/2" long, truncate; blades 1"-3" wide, rough, those of the culm 4'-9' long, the basal narrow and about one-half of the length of the culm; panicle 3'-6' in length, its branches drooping and flexuous, at least when old, the nodes of the axis pubescent; spikelets 5-10-flowered, 9"-15" long, on slender flexuous pedicels; empty scales pubescent, the first narrower than the second, both 3-nerved; flowering scales 5"-6" long, obtuse, 5-7-nerved, densely pubescent with long silky hairs; awn 1 "-2" long.
In dry soil, South Dakota to Montana, south to western Nebraska, New Mexico and Arizona. July-Aug.
Bromus Kalmii A. Gray, Man. 600. 1848.
Culms 1 1/2°-3° tall, erect, simple, smooth and glabrous. Sheaths shorter than the internodes, more or less pubescent; ligule very short; blades 21/2'-7' long, 1"-4" wide, sparingly pubescent; panicle 2'-6' in length, open, its branches usually flexuous; spikelets 6-10-flowered, 6"-12" long, on slender flexuous pedicels; empty scales pubescent, the first narrow, acute, 3-nerved, the second longer, broad, obtuse or mucronate, 5-7-nerved; flowering scales about 4" long, 7-9-nerved, densely silky pubescent, the awn 1"-1 1/2" in length.
Bromus hordeaceus L. Sp. PI. 77, 1753. Bromus mollis L. Sp. PI. Ed. 2, 112. 1762.
Culms 8'-3° tall, erect, often slender, usually pubescent below the panicle. Sheaths shorter than the inter-nodes, mostly pubescent; ligule 1/2" long; blades 1-7' long, 1"-3" wide, pubescent; panicle generally contracted, its branches erect or ascending, 1'-2' long; spike-lets appressed-pubescent, on short pedicels; empty scales acute, the first 3-nerved, the second longer, 5-7-nerved; flowering scales broad, obtuse, 3 1/2"-4 1/2" long, 7-9-nerved, bearing an awn 3"-4." in length between the obtuse or acute teeth.
In fields and waste places, Nova Scotia to British Columbia, California and North Carolina. Locally adventive from Europe. Soft Brome. Haver-grass. Blubber-, Hooded-, Bull-, Lob- or Lop-grass. July-Aug.