DISEASES OF CEREALS AND GRASSES 



3:) 



not so dark in colour as those of P. graininis, have 

 a much shorter stalk, and are not covered with a 

 crown of paraphyses or hairs. 



The secidia are found on the bugloss, but are 

 not essential, for uredospores may be found on 

 young wheat and rye plants in the autumn, and the 

 mycelium is undoubtedly able to rest there over 

 winter, as well as in various grasses, and on account 

 of this is most difficult to combat. 



A 



Fig. 14. — (A) uredospores of Piiccinia graminis ; (B) teleutospores of 

 Piucinia gi'aininis : (C) UTcdohi^ores oi Pticcinia gliiiiuintHi : (D) tel- 

 eutospores of Puccinia gluniariim ; (E) uredospores of Piicciiiia 

 coroiiata ; (F) teleutospores of Puccinia coronatd : notice the crown 

 of spiney projections at the end. (All highly magnified.) 



For preventive measures see p. 54. 



(d) Barley Rust [Ptcccinia suiiplex, Korn). 

 Attacks barley, but the damage is only slight. 



The teleutospores are mostly one celled. 



(e) Crown Rust of Oats and Grasses [Puccinui 

 coronata, Corda). 



