Aug. 2 7, 191 7 Puccinia graminis on Cereals and Grasses 



447 



Elymus condensatus was almost universally rusted both west of the 

 Rocky Mountains and in Montana, Wyoming, and western Nebraska 

 east of the mountains. Unfortunately no inoculations were made with 

 the rust from east of the mountains, which would very probably have 

 proved to be ordinary P. graminis tritici. All of the rust which was used 

 in the inoculations, the results of which are recorded in Table XV, was 

 P. graminis tritici compacti. 



Diagram 6. — Results of inoculations with urediniospores from Elymus glaucus Buckley. 



[Rye :-; 7 



Puccinia araini-nis from Elymus glaucus 

 (Ellensburg, Wash.). 



Wheat 



016 

 17 



Barley 



Barley 



Oats 



Wheat 



Club wheat — 

 17 



o Wheat very sharply hypersensitive, 

 b Heavy, normal infection on club wheat. 



The character of infection on bluestem wheat, Minnesota 169, shows 

 clearly that the rust was P. graminis tritici compacti. The uredinia were 

 always small, and there were large dead spots on the leaves. On barley 

 and club wheats on the other hand, infection was normal. 



Tabi<E XVI. — Results of inoculations with urediniospores from Elymus macoimii 



Vasey 



a Wheat and rye hypersensitive. 



The rust collected at Winnipeg and Emerson, Manitoba, and that col- 

 lected at Havre, Montana, was all ordinary P. graminis tritici, while that 

 collected at Ellensburg, Wash. , was P. graminis tritici compacti. Both attack 

 the grass very easily and may produce large numbers of spores on it. 

 Although P. graminis secalis was not found on Elymus macounii in the 

 field, it is quite possible that the grass is susceptible to this form, since 

 the various species of Elymus seem to be quite similar in this respect 

 (Table XVI). 



