640 Rydbjbrg: Phytogeographical notes 



Northern Rockies 

 Stipa Richardsonii Elynius innovatiis 



" Lettermannii ^Agropyron latiglume 



Poa Cusickii " spicatum 



" nevadensis 



5. Hog-backs and Dry Ridges 



The flora here consists mostly of grasses from the Great Plains 

 intermixed with some elements from the Subalpine Zone. The 

 grass flora is rather poor in number of species. This is especially 

 the case if those common to the hillsides are eliminated. The 

 flora includes the following grasses: 



*Aristida longiseta Poa crocata 



* " Fendleriana f " paddensis 



Stipa viridula fFestuca brachyphylla 



*Calamagrostis purpurascens f " saximontana 



Avena americana '\Agropyron andinum 



Danthonia intermedia f " Scrihneri 



Boiitelotia oligostachya " spicatum 



*Koeleria gracilis 



The following are restricted to one region : 

 Southern Rockies Northern Rockies 



Stipa Vaseyi ]Poa Cusickii 



\Mulilenhergia suhalpina *Festuca campestris 



" filiculmis \Sitanion rigidum 



Poa Fendleriana " lanceolatum 



To the preceding formations may be added the following five 

 in which the grasses do not constitute the principal or predominant 

 species : 



6. Woods 



The truly wood species of grasses are very few, and even 

 these do not grow in the deep forest but in more open places. 

 They are the following: 



Oryzopsis asperifolia Poa compressa 



Cinna latifolia Festuca^-Jonesii 



Avena striata 



