GRASSES OF IOWA. 



217 



SMUTS — USTIL A GINE.E . 



The Ustilaglnese are popularly known as smuts and are well 

 known to all farmers, at least those affecting our cereal grasses. 

 Among the several hundred species those of cereals are most 

 destructive, entailing a loss to the farmer every year of millions 

 of dollars. 



A large number of the economic grasses are likevvis3 affected, 

 but these are not so often observed, though the loss in many 

 cases is quite serious. I have not attempted to discuss 

 all of the smuts of our economic grasses, though I have given 

 short accounts of the more important, and especially the smuts 

 of cereals. Many important studies have been made in this 

 country especially of our economic spscies. Kellerman and 

 Swingle, Arthur and other mycologists have made important 

 contributions to our knowledge of Ustilagineae. I have freely 



Fig. 104. Maize smut, Ustilago maydis. Ear aflfected, e, smut boils; r, liernels; c, 

 bracts. 



Fig. 105, Smut boil making Its appearance at the node. (King.) 



