Genus 106. 



GRASS FAMILY. 



289 



Empty scales narrowly subulate. 



Spikelets hirsute. 15. E.striatus. 



Spikelets glabrous or hispidulous. 16. E. arkansanus. 



Empty scales variable in length, from a short point to longer than the spikelet, even in the same spike. 



1 7. E. diversiglumis. 



i. Elymus Macounii Vasey. Macoun's Wild Rye. 

 Fig. 700. 



Elymus Macounii Vasey, Bull. Torr. Club 13: 119. 1886. 



Culms i°-3° tall, erect, simple, smooth and glabrous. 

 Sheaths shorter than the internodes; ligule very short, 

 truncate; blades 2'-6' long, i"-2i" wide, rough, especially 

 above; spike 2'-$' in length, narrow, slender, often some- 

 what flexuous; spikelets appressed to the rachis, single 

 at each node, or the lower sometimes in pairs, 1-3-flow- 

 ered; empty scales (occasionally 3) awl-shaped, 3-nerved, 

 rough, 3"-4" long, bearing a slender straight rough awn, 

 3"-S" in length; flowering scales 3¥'-$" long, rough 

 toward the apex, bearing a slender straight awn $"-$" long. 



Prairies, Manitoba to Athabasca, Minnesota, Missouri and 

 New Mexico. July-Aug. 



2. Elymus glaucus Buckl. Smooth Wild Rye. 

 Fig. 701. 



Elymus glaucus Buckl. Proc. Acad. Phila. 1862 : 99. 1862. 

 Elymus americanus V. & S. ; Macoun, Cat. Can. PI. 4: 245. 



1888. 

 Elymus sibiricus var. americanus Wats. & Coult. in A. Gray, 



Man. Ed. 6, 673. 1890. 



Culms 2°-5° tall, erect, simple, smooth and glabrous. 

 Sheaths often shorter than the internodes, usually 

 glabrous, rarely pubescent; ligule 1" long or less; blades 

 4'-i2' long, 2"-8" wide, smooth beneath, sometimes 

 rough above; spike 3'S' in length, narrow, slender; 

 spikelets appressed to the rachis, 3-6-flbwered ; empty 

 scales narrowly lanceolate, 4"-6" long, acuminate or 

 awn-pointed, rigid, 3-5-nerved; flowering scales smooth 

 or slightly rough, s"-6" long, bearing a slender straight 

 rough awn 6"-o" in length. 



In moist soil, Ontario and Michigan to British Columbia, 

 south to Colorado and California. June-Aug. 



3. Elymus vulpinus Rydb. Rydberg's 

 Wild Rye. Fig. 702. 



E. vulpinus Rydb. Bull. Torr. Club 36: 540. 1909. 



Culms ii°-2i° tall, erect, slender, tufted, 

 smooth and glabrous. Sheaths smooth, usually 

 shorter than the internodes; ligule a short mem- 

 branous ring; blades erect, 4'-6' long, i"-3" wide, 

 acuminate, smooth beneath, scabrous on the mar- 

 gins and sometimes also sparsely so above ; spike 

 slender, long-exserted, 4'-6' long ; spikelets usually 

 in pairs, rarely single, somewhat crowded, ap- 

 . pressed to the rachis, more or less compressed, 

 4-6-flowered ; empty scales 4"-s" long, shorter 

 than the spikelet, acuminate into a shorter awn; 

 flowering scales 4"-s" long, , acuminate, bearing 

 a slender scabrous awn, 4"-S" long. 



Bottom lands, western Nebraska. Admitted into 

 first edition of this work as Agropyron Gmelini 

 Scribn. & Sm. 



19 



