RHYTISMA. 195 



R. salicinum. Fr. 



Almost the same characters as the R. Ilicis-Canadensis, only 



that it has a different host. 



Common on willow leaves. Leaves look as though they were sprinkled 

 with pitch. 



R. acerinutn. Maple Rhytisma. 



Spermagonia present in form of orbicn^r pustular spots, 

 with a discolored zone. 



Ascophore spots irregular, confluent, rugose, bursting 

 irregular, di?c growing pale. 



Scarce on our maple tree leaves. 



