GRAMINEAE. 



VOL. I. 



16. Elymus arkansanus Scribn. & Ball. Smooth 

 Slender Wild Rye. Fig. 715. 



Elymus arkansanus Scribn. & Ball, Bull. U. S. Dep. Agr. 

 Agrost. 24: 45. /. 19. 1901. 



Culms 2-3 tall, slender, erect; sheaths glabrous, 

 rarely the lower pubescent ; blades up to 8' long, 2,"-^" 

 wide, rough on the lower surface, appressed-pubescent 

 on the upper surface ; spike 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 io"-2o" 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. 



17. Elymus diversiglumis Scribn. & Ball. 

 Various-glumed Wild Rye. Fig. 716. 



Elymus diversiglumis Scribn. & Ball, Bull. U. S. Dep. 

 Agr. Agrost. 24: 48. /. 22. 1901. 



Culms 2i-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 spar- 

 ingly hirsute, the hispidulous awn io"-i5" long. 



Wisconsin and Minnesota to North Dakota and Wyo- 

 ming. July and Aug. 



107. HYSTRIX Moench, Meth. 294. 1794. 



Usually tall grasses, with flat leaf-blades and 

 terminal spikes. Spikelets 2-several-flowered, in 

 pairs, rarely in 3*5, at each node of the rachis. 

 Empty scales wanting, or sometimes appearing as 

 mere rudiments ; flowering scales narrow, convolute, 

 rigid, rounded on the back, 5-nerved above, terminating in an awn ; palet scarcely shorter than 

 the scale, 2-keeled. Stamens 3. Styles very short, distinct. Stigmas plumose. Grain oblong, 

 adhering to the palet when dry. [Greek name of the Porcupine, referring to the long awns.] 



Four species, the following and a Californian one 

 in North America. Type species : Elymus Hystrix 



i. Hystrix Hystrix (L.) Millsp. Bottle- 

 brush Grass. Fig. 717. 



Elymus Hystrix L. Sp. PI. Ed. 2, 124. 1762. 

 Asprella Hystrix Willd. Enum. 132. 1809. 

 Gymnostichnm Hystrix Schreb. Beschr. Gras. 2: 127. 



pi. 47. 1810. 

 Hystrix Hystrix Millsp. Fl. W. Va. 474. 1892. 



Culms 2-4 tall, erect, simple, smooth and 

 glabrous. Sheaths usually shorter than the in- 

 ternodes ; ligule very short ; blades 4i'-o/ long, 

 3"-6" wide, smooth beneath, . rough above; 

 spike 3'-7' in length; spikelets at length widely 

 spreading, 4"-6" long, exclusive of the awns ; 

 empty scales awn-like, usually present in the 

 lowest spikelet ; flowering scales 4"-6" long, 

 acuminate into an awn about i' in length. 



In rocky woods, New Brunswick to Ontario, south 

 to Georgia, Illinois and Nebraska. Spikelets easily 

 detached, even when young. Bottle-rush. June- 

 July. 



