844 POACE^. 



above its glume ; palea very nearly as long as its glume, erose or 2- 

 toothod. 



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

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

 brandies at each joint flower-bearing to the base. From D. Cana- 

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

 shorter hairs surrounding the flowering glume, and firmer and longer 

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

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

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

 tionally longer." The specific name diibin was used with Calama- 

 grosfis by Uunge, Lehm. Rel. 348 (1847), lience the change ahove 

 to Scribneri, for the discoverer. 



Montana (Yellowstone Park), Tweedy 365. 



Montana, Washington, Oregon. 



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

 Ariindo Lan(isdorff{ili\xxk, Ilort. Bei'ol. 1:74 (1821). Deyeuxia 

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



Much the same as 6^. Canadensis, excepting tlie 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, truncato-tootlied, 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, WiUiams. 



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



12. C. Vaseyi. Ariindo pnrpvrascns Schult. Mant. 3:603 

 (1824). Degcnxia jmrjmrascens Kunth, Rev. Gram. 1:7 (1829), 

 not Calamagrnstis purpvrascens R. Br. Richards, App. Frank, 

 which is D. sylratica Kunth. 



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

 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 



