THE FUNGI WHICH CAUSE PLANT DISEASE 



217 



Spores hyaline 



Spores 1-celled 16. Scirrhiella. 



Spores 2-celled 17. Scirrhia. 



Spores 4 to 8-celled, fusiform. . . 18. Monographus. 

 Spores colored, multicellular, fusi- 

 form 19. Rhopographus. 



Stromata sunken, permanently united to 

 the epidermis and substratum 



Spores 1-celled 20. Phyllachora, p. 220. 



Spores 2-celled 



Spores of similar cells 21. Dothidella, p. 221. 



Spores of dissimilar cells 22. MunMella. 



Stromata from the first superficial 

 Stromata encrusted, widely spreading. . . 23. Hyalodothis. 

 Stromata cushion-shaped, limited 24. Schweinitziella. 



Of these genera only five are of interest as plant pathogens. 

 The majority contain only saprophytes. 



Diachora Muller (p. 216) 



The genus is easily recognized by its peculiarity of bearing asci 

 only as an equatorial band instead of -^ -_ 



on the floor of the perithecia, a char- * ' 



acter unique among the Pyrenomy- 

 cetes. 



D. onobiychidis (D. C.) Miill. is 

 reported as causing black spots on 

 leaves of sainfoin and Lathyrus in 

 Europe. 



Plowrightia Saccardo (p. 216) 



Stromata formed within the tissues 

 of the host plant, erumpent, tuber- 

 cular or cushion-shaped, depressed or 

 elevated, smooth, later frequently wrinkled, white within; asci 

 cylindric, 8-spored; spores ovate, 2-celled, hyaline or light green; 

 conidial forms Cladosporium, Dematium, etc. 



Fio. 154. — D. onobrychidis. E, co- 

 nidial stage; F, ascocarp and asci. 

 After Muller. 



