DISEASES CAUSED BY FUNGI 



37 



proper (Euascomycetes) contain an enormous number of species, 

 a fair number of which are plant parasites. 



The Erysiphaceae or powdery mildews (see p 20) and the 



W'^. 



Fig. 8 ASCOMYCETES 

 1. Peziza. 2. Balansia trinitensis. 3. Scleroderris. 

 4. Perithecia and Conidia of an Erysiphe. 5. Nectria 

 6. Xylaria. 7. Hypoxylon. 8. Pseudovalsa. 



From Engler & Prantl. Nat. Pflanz. 



Perisporiacese (which include the fungi of "black blight") have 

 mycelium which is superficial on the host plant, commonly on 

 leaves, and have the asci enclosed in more or less spherical 



