18 



JOURNAL OF MYCOLOGY. 



Hyphomycetous fungi growing mostly on living leaves, generally on 

 dead or discolored spots, and consisting of little tufts of erect, brown, or 

 sometimes nearly colorless (hyaline) threads (hyphie) bearing terminal 

 or (exceptionally) lateral, elongated, septate, pale brownish or hyaline 

 spores (conidia) which are generally attenuated above. The hyphse 

 arise from a more or less distinct tubercular base and are generally 

 undulate above or are abruptly bent this way and that, or imperfectly 

 toothed and swollen at intervals (nodulose) and occasionally sparingly 

 branched. The c inidia are, for the most part, terminal, but occasion- 

 ally arise also from little tooth-like projections on the sides of the 

 hyphse below the apex. They are cylindrical, hyaline and without septa 

 (continuous) at first but soon become elongated and septate, and are 

 usually attenuated above, of ten very distinctly so, and at maturity 

 become slightly brownish, but in most of the species this brown tint is so 

 faint that the conidia are called hvaline. There are, however, species 

 with decidedly browm conidia (Nos. 25, 27, 101.) 



Cercospora is confluent on one side with Helminthosporium from 

 which it differs in its less rigid and paler hyphse and conidia, and on the 

 other with Bamularia which has both hyphse and conidia hyaline. Prob- 

 ably none of the species are a itonomous, being apparently only the coni- 

 dial stage of various species of Sphcerella or other sphseriaceous fungi. 



Thanks are due to Dr. Geo. Martin, of West Chester, Pa., who has 

 carefully examined many of the species here describe! and placed his 

 notes at our disposal. 



The species may be grouped, for convenience, according to the pres- 

 ence, absence, color, etc., of the spots. 



A. Hyphse brown. 



a. Spots orbicular or suborbicular. gray, cinereous or white, 1-19. 



b. " " " brown, at least when young, 20-50. 



c. Spots angular or irregular, 51-()5. 



d. Spots indefinite. 66-75. 



e. Spots none, or at least not very conspicuous. 



a. Tufts scattered, 76-82. 



b. Tufts effused, 83-101. 



B. Hyphse nearly hyaline (Cercosporella, Sacc), 102-lOS. 



C. Species standing ambiguously between Cercospora and Ram- 



ULARiA, 109 et seq. 



A. Hyphse brown. 



a. SiMs orbicular or suborbicular, gray, cinereous or white. 



1. Cercospora flaoellaris, E. &M., Am. ^^at., Dec. '82, p. 1003. 

 N. A. P., 1256. 



Spots pallid-white (2— S mm.) with a narrow, raised, reddish brown 

 border, round or irregular, often confluent, mostly on withered parts of 

 tJie leaf. Hyphse tuftsd, brownish, undulate and nodulose above. 75—80 



