556 THE FUNGI WHICH CAUSE PLANT DISEASE 



CI^N ' 100-120 /I, or by confluence larger; 

 I /vO conidia abundant, clavate or wedge- 



\_^ shaped, 11-15 x 2.5-3 n. 



The cause of leaf perforations of 

 lettuce. 

 M. violae (Pass.) Sacc."' 

 Discoloration of the host slight; 

 ^_^^-^ 2^:^^yy acervuli nvunerous, scattered, small; 



,,^ (f""" ■ conidia curved, or straight, 15-18 x 



yK^;;;~-y^ J 5-6 ii, septum usually excentric. 

 T,_ „,, ., , Small spots are produced on violet 



Fig. 374. — Marssonia violse. 



Spores and conidiophores. leaveS. 



After Jones and Giddings. j^_ medicaginis Vors. is on alfalfa. 



Melanconiacese-Phseodidymse (p. 537) 

 Conidia dark, 1-septate, ovoid to fusoid. 



Ket to Genera of Melanconiaceae-Phsodidyinse 



Conidia solitary 



Conidia muticate 1. Didymosporium, p. 556. 



Conidia 1 to 3-ciliate at apex 2. Neobarclaya. 



Conidia catenulate, connected by hyaline 



isthmi 3. Bullaria. 



Didymosporium Nees 



Acervuli roimded or elongate, covered, erumpent; conidia elon- 

 gate or fusoid. A genus of less than twenty species. 

 D. salicinum Vuill is on poplar. 



Melanconiaceae-Hyalophragmise (p. 537) 

 Conidia hyaline, 2 to several-septate, oblong to fusoid or clavate. 



Key to Geneea of Melanconiacese-Hyalophragmiie 

 Conidia separate 

 Conidia muticate 

 Conidia oblong or fusoid, masses usually 



pale 1. Septogloeum, p. 557. 



