344 POACE^. 



above its glume; palea very nearly as long as its glume, erose or 3- 

 toothed. 



Professor Scribner says : "It differs from both in tlie less spread- 

 ing and more densely flowering branches of the panicle, the stouter 

 branches at each Joint flower-bearing to the base. From D. Cana- 

 densis it is at once distinguished by the longer and stouter awn, 

 shorter hairs surrounding the flowering glume, and firmer and longer 

 palea. The spikelets are smaller than in D. Langsdorffii, the 

 empty glumes are much smoother and less rigid or firm in texture, 

 the hairs are less copious as well as shorter, and the palea is propor- 

 iionally longer." The specific name dubia was used with Calama- 

 •grostis by Bunge, Lehm. Rel. 348 (1847), hence the change above 

 to Scrihneri, for the discoverer. 



Montana (Yellowstone Park), Tweedy 365. 



Montana, Washington, Oregon. 



11. C. Langsdorffii (Link) Trin. Unifl. 225, t. 4, fig. 10 (1824). 

 Arundo Langsdorffii lAvik, Hort. Berol. 1:74 (1821). Deyeuxia 

 Langsdorffii Knnth, Rev. Gram. 1:77 (1829). 



Much the same as 0. Canadensis, excepting the ligule may be 

 8-12 mm. long, the spikelets 4-6 mm, long, empty glumes atten- 

 uate-acuminate, first 1-3-nerved, second a little shorter, 3-nerved; 

 floral glume 3.5-4 mm. long, oval, truncate-toothed, awn straight, 

 stouter, attached a little below the middle, hairs longer than the 

 floret, or of the same height or a little shorter; rudiment 1-1.7 mm. 

 long, with hairs extending to the tip of the floret. 



New Hampshire, Pringle ; Minnesota, Geol. Surv., B 519; 

 Montana, Williams. 



Canada, New Hampshire, to the Rocky Mountains and Alaska. 



12. C. Vaseyi. Arundo purpurasens Schult. Mant. 3 : 603 

 (1824). Deyeuxia ptirpurascens Kunth, Rev. Gram. 1:7 (1829), 

 not Calamagrostis purpurascens R. Br. Richards, App. Frank, 

 which is D. sylvatica Kunth. 



A tufted, rather slender perennial, 60-75 cm. high. Sheaths 

 about 5 in number, mostly half to two-thirds as long as the inter- 

 nodes; ligule lacerate, 3-4 mm. long; blades flat, scabrous, long- 

 pointed, 15-20 cm. long, 4-8 mm. wide, with a ring of short hairs at 



