Parasitic Fungi of Illinois. 



39*? 



Figure 7. Podosphsera 

 ooeycanthx, (DC.) DBy.: a, 

 pericthecium with dichoto- 

 mously forked appendages 

 J, — magnified 90 times ; c, a 

 tip of an appendage more 

 magnified ; 6, the single ascus 

 with eight spores, — magni- 

 fied 325 times. 



Fig. 8. 



Figure 8. Microsphsera 

 SavmeiajBeik.: a,perithecium 

 with its dichotomously forked 

 appendages 6, — magnified 75 

 times ; c, a tip of an appendage 

 more magnified ; d, one of the 

 several asci containing eight 

 spores, — magnified 375 times; 

 e, a group of asci from one 

 perithecium, — magnified 150 

 times. 



Key to the Gejteba of Eeysiphb^. 



I. Appendages consisting of simple threads similar to the 



mycelium, and often interwoven with it A. 



II. Appendages dissimilar to, and free from the mycelium . B. 



A. Perithecia containing only one ascus . . SpHiBROTHECA. 

 Perithecia containing several asci Eetsiphe. 



B. Appendages simple, not usually forked at the tip. . .1. 

 Appendages dichotomously forked at the tip 2. 



1. Appendages coiled at the tip, asci several. 



U]>rCIN"ULA. 



Appendages needle-shaped, abruptly swollen at 

 base, asci several Phtllactinia. 



2. Perithecia containing only one ascus. 



PODOSPH^KA. 



Perithecia containing several asci . Microsph^ea. 



