26 



on the prairie rose, formerly called Rosa arkansana, now known 

 as R. pratincola, and extends from northern Illinois to Kansas and 

 northward. P. montivagurn is found in the Rocky Mountains 

 from southern Colorado and Salt Lake in Utah northward. It 

 occurs on all or nearly all the many species of native roses of this 

 region, having been reported on Rosa Bakeri, R. Fendleri, R. 



'^/^///, /hr. arneri can um 



P/tr. Ro^ae-^s&t fjerae 



rh r. mont/y o-ju m. 

 ^^ PAk Rosae'Co-liforniccLe 



Fig. 3. Distribution of the five American species of Phragmiaium occurring 



on native roses. 



grosse-serrata, R. ma?tca, R. Maximiliani, R. Sayi, R. Under- 

 woodii, R. Woodsii, and others. P. Rosae-californicae extends 

 along the Pacific coast from southern California to southwestern 

 Alaska, on Rosa californica, R. gyinnocarpa, R. pisocaj'pa, and R. 

 acicidaris chiefly. 



It will be observed that there are large areas from which no 



