ERVSIPHE. 203 



(;enus XV. UNCINUlvA. Lev. 



Mycelium floccose, appendages rigid, simple, bifid or simple, 

 uncinate, at length bent upwards. 



U. salicis. Winters. 

 Perithecia, abundant on the upper surface of different 

 species of willow and poplar. 



Asci, oval, containing from four to six sporidia. 

 Jungle near Trexlertown, Pa. 



U. necator. Schw. 



Perithecia, medium size, dark colored so as to be easily 

 distinguished. 



Asci, ovate, acuminate, containing from four to six sporidia. 



Appendages slender, the outer half hyaline, tips loosely 

 coiled. 



Common on our Virginia creeper. This is supposed to be, and no 

 doubt is, the Uncinula spiralis, B. and C, or the powdery mildew on the 

 grapevine. 



The law of priority favors Ellis and Everhart's decision in their North 

 American Pyrenomycetes, where they are taken as the Uncinula necator. 



Genus XVI. BRYSIPHB. Hedw. 



Mycelium spiderweb-like, appendages floccose, simple or 

 irregularly branched. This genus is the type of this natural 

 order, being also named Erysipheae. 



B. graminis. Grass Blight. 

 Perithecia, epiphyllous, large, mycelium effu.sed, flocco.se ; 

 appendages simple or interwoven with the mycelium. 



On leaves of grapes. The conidia spores are the Oidiuni moniloides. 



