OKDER ERYSIPHALES (PERISPORIALES OF MOST AUTHORS) 



309 



Erysiphaceae in what is called here the Order Hypocreales, Meliola and 

 Amazonia in the Dothideaceae, the Atichiaceae in the Myriangiales and 

 various Capnodiaceae in the Sphaeriales. 



Family Erysiphaceae (The Powdery Mildea^s). These fungi are 

 parasitic upon Flowering Plants (Anthophyta) the world over, reaching 

 their greatest development in the temperate zones. They are usually con- 

 fined to leaves and young tissues of other portions of the plant, such as 



Fig. 97. Erysiphales, Family Erysiphaceae. (A) Erysiphe graminis DC. Haustoria 

 in epidermal cells of host, seen from above. (B, C) Phyllactinia guttata (Wallr.) Lev. 

 Mycelium in substomatal chamber of host. (D) [Leveillula taurica (Lev.) Arnaud. 

 External and internal mycelium, and conidiophore. (After Arnaud: Ann. ^viphvt., 

 7:1-115.) ^ ' 



