GENUS 106. 



GRASS FAMILY. 



289 



Empty scales narrowly subulate. 



Spikelets hirsute. I5 . E. striatus. 



Spikelets glabrous or hispidulous. : 6. E. arkansamts. 



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



17. 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, \"-2.\" 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, i-3-flow- 

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

 rough, 3"--)." long, bearing a slender straight rough awn, 

 3"-5" in length ; flowering scales 3i"~s" long, rough 

 toward the apex, bearing a slender straight awn 3"-5" 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 amcricanus V. & S. ; Macoun, Cat. Can. PI. 4- 24.*. 



1888. 

 Elymus sibiricus var. americanns 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 i" long or less; blades 

 4/-I2' long, 2"-8" wide, smooth beneath, sometimes 

 rough above; spike 3 '-8' in length, narrow, slender; 

 spikelets appressed to the rachis, 3-6-flowered ; 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" -9" 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. vulpiints Rydb. Bull. Torr. Club 36: 540. 1909. 



Culms i2-2* 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" -5" long, shorter 

 than the spikelet, acuminate into a shorter awn ; 

 flowering scales 4" -5" long, acuminate, bearing 

 a slender scabrous awn, 4" -5" long. 



Bottom lands, western Nebraska. Admitted into 

 first edition of this work as Agropyron Gmelini 

 Scribn. & Sm. 



19 



