52 FUx\GOID DISEASES 



(b) Golden or Spring Rust [Ptcccinia glu- 

 niarimi). (Fig. 14, C and D). This rust was pre- 

 viously considered as a variety of P. riibigo vera, 

 but Erikson, as a result of inoculation experiments, 

 considers it a distinct species with several bio- 

 loofical varieties. 



The roundish uredospores appear on the leaves 

 of grasses, in the form of lemon to cadmium coloured 

 irregular pustules or sori. These sori may spread 

 longitudinally, forming ultimately yellow linear 

 markings. The teleutospores are sparse, and in 

 the form of fine brownish-black stripes. 



The teleutospores are set on short stalks and 

 germinate in the autumn of their formation. The 

 pro-mycelium is of a bright yellow colour — this dis- 

 tinguishes it from Puccinia dispei'sa — which colour 

 disappears on the formation of the sporidia. 



The cecidial stage is unknown. 



Although abundant in spring, the damage done 

 is not serious. 



For preventive measures see p. 54. 



(f) Broivn Rust {Puccmia rubigo vera = Puccinia 

 straminis, Fuckel ; Pnccinia dispersa, Erikson). 



This rust is found chiefly on the leaves of rye, 

 wheat, barley, and various grasses, in the form of 

 rust-red, roundish, scattered patches. The uredo- 

 spores are much rounder than those of P . graviinis. 



The teleutospores are present in the same pustule, 

 in fact, spring from the same mycelium ; they are 



