170 THE FUNGI WHICH CAUSE PLANT DISEASE 



Myriangiacese (p. 165) 



Perithecia numerous upon or in a stroma; asci in a pseudo- 

 parenchymatous substance within the perithecium; spores muri- 

 form. 



Key to Genera of Myriangiacese 



Stroma valsoid, perithecia superficial. ... 1. M}niaiigium. 

 Stroma effused, perithecia immersed 2. Mjrriangiella, p. 170. 



M]rrangiella orbicularis Zimm. parasitizes coffee in Java.^"" 



Pyrenomycetes '* 



The four following orders are usually grouped together as the 

 Pyrenomycetes; separated from the preceding forms by their closed 

 ascocarp with the asci arranged in a hymenium. They constitute 

 a vast assemblage of more than ten thousand species, the large 

 majority saprophytic and unimportant except in the general 

 economy as scavengers. 



Perisporiales (p. 124) 



The present order is characterized by its almost universal 

 parasitic habit, the evident myceUum and the globoid perithecia 

 without ostioles, or in one family flattened, ostiolate perithecia. 

 The mycelium is superficial upon the host and frequently quite 

 conspicuous. 



Key to Families of Perisporiales 



Perithecia mostly spherical, imperforate 

 Mycelium white; perithecia with append- 

 ages 1. Eiysiphacese, p. 171. 



External mycelium dark colored or want- 

 ing, perithecia without true append- 

 ages, but sometimes surrounded by 



appendage-like hyphae 2. Perisporiaceae, p. 189. 



Perithecia flattened, shield-shaped, ostio- 



lat« 3. Microthyriaces, p. 195. 



