CEREAL PESTS PARASITIC FUNGI 509 



Closely allied to the preceding is another oat rust 

 (P. coronifera, Kleb.), also known by the common name 

 crown-rust. It is as widely distributed as is P. coronata, 

 and so closely does it resemble this species that it is dis- 

 tinguished from it only by minute differences and the 

 fact that, with but few exceptions, it occurs on different 

 hosts. The aecidial host of P. coronifera is Rhamnus 

 cathartica, a European species of buckthorn widely 

 planted as a hedge plant in the eastern United States, 

 which in some localities has even become sparingly 

 naturalized. 



554. The yellow or stripe-rust (Puccinia glumarum, 

 Eriks. & Henn.). This rust has just been discovered in 

 this country during the past year (June, 1915), and there- 

 fore little can be stated yet as to its distribution and dam- 

 age in North America. Wherever it occurs in the other 

 countries it is often the most serious rust. It was identi- 

 fied some years ago by Eriksson and Henning (1894) as 

 a species distinct from the orange leaf -rust, with which it 

 had been previously confused. The chief characters per- 

 mitting it to be readily distinguished at sight from all 

 other cereal rusts are (1) the bright yellow color of the 

 uredo stage and (2) the peculiar arrangement of the sori 

 in extremely long fine lines between the veins of the leaf. 

 The rust attacks first and chiefly the leaves, but passes 

 later to all parts of the plant, and is more common on the 

 spikes than any other species. 



The yellow rust attacks all the cereals, except oats, and 

 many wild grasses. In this country it has been found so 

 far on barley, wheat, rye, wild barley, species of Elymus, 

 and Bromus inermis. It appears already to be very dam- 

 aging to club wheat, and is quite prevalent in Oregon, 

 Washington, and Idaho. 



