MANUAL OF THE GRASSES OF THE UNITED STATES 



45 



Mountains) (fig. 24). B. richardsoni Link is a form that has been 

 distinguished by its larger spikelets and lemmas and more robust 

 habit, but it grades freely into B. ciliatus and can scarcely be ranked 

 even as a variety. This is the common form in the Rocky Mountains. 

 Bromus ciliatus var. laeviglumis Scribn. Culms stout, leafy, 

 mostly more than 1 m tall; sheaths shorter or longer than the inter- 

 nodes, glabrous to pubescent, not strongly pilose; blades elongate, 



Figure 24.— Distribution of 

 Bromus ciliatus. 



Figure 25.— Distribution of 

 Bromus purgans. 



Figure 26.— Distribution of 

 Bromus latiglumis. 





as much as 1 cm wide or even wider; panicle large, open; lemmas 

 glabrous or nearly so. — Woods and river banks, rare. Known from 

 Maine, Vermont, New York, Ontario, Michigan, North Dakota, 

 Maryland, West Virginia, Virginia, North Carolina, and Kansas. 



16. Bromus purgans L. Canada brome. (Fig. 23, B.) Resem- 

 bling B. ciliatus; nodes mostly 4 to 6; sheaths, except the lower 1 or 2, 

 shorter than the internodes, more or less retrorsely pilose, or some- 

 times all glabrous; blades narrowed at base, and without flanges or 

 auricles; pubescence of lemma nearly uniform, sometimes more dense 

 on the margins, sometimes sparse and short on the back or scabrous 

 only. % — Moist woods and 

 rocky slopes, Massachusetts to 

 Alberta, south to northern Florida 

 and Arizona (fig. 25). 



17. Bromus latiglumis (Shear) 

 Hitchc. (Fig. 23, C.) < Differing 

 from B. purgans in having usually 

 10 to 20 nodes; sheaths overlap- 

 ping, longer than the internodes, 

 more or less pilose, especially about 

 the throat and coUar; base of blades 

 with prominent flanges on each 

 side, these usually prolonged into 

 auricles. Where the ranges of B. 

 purgans and B. latiglumis overlap, 

 the latter flowers several weeks later 

 than the other. % — Alluvial 

 banks of streams, Maine to eastern 

 Montana, south to North Carolina and Oklahoma (fig. 26). A form 

 with densely canescent sheaths has been called B. incanus (Shear) 

 Hitchc. — Vermont to North Dakota, south to Pennsylvania, Dela- 

 ware, Maryland, Ohio, and Iowa; western Texas, Colorado, and New 

 Mexico. 



18. Bromus texensis (Shear) Hitchc. (Fig. 27.) Culms slender, 

 mostly solitary, 40 to 70 cm tall; sheaths much shorter than the 



Figure 27.— Bromus texensis, X 1. 

 (Tracy 8881, Tex.) 



