620 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Fia. 418. — Macro- 

 sporium cucumer- 

 iuum on cante- 

 loupe. After 

 Chester. 



mm. in diameter; conidiophores fasciculate or 

 solitary, subgeniculate, 1 to 3-septate, 35-50 x 

 5-6 m; conidia clavate, slender-stipitate, 3 to 

 8-septate, somewhat constricted, submuriform, 

 30-75 X 15-25 n; pedicel 25-35 /i long. 



On leaves, stems and fruits of cantaloupes. 



M. cladosporioides Desm. is on beet, lettuce, 

 onion and many other hosts. 



M. verrucosum I.utz. occurs on cacao; 



M. gramineum Cke.'^* on sugar cane. 



M. uvarum Thum. is reported on Vitis; 



M. violae Poll, on violets in Italy; 



M. saponaris Pk. on Saponaria. 



M. macalpinianum S. &. Sy. is injurious to 

 Pelargonium. 



Mystrosporium Corda (p. 616) 



Conidiophores simple or sparingly branched, short, septate, 

 fuscous, rigid; conidia elliptic, subglobose or oblong, pluriseptate, 

 muriform, dark, usually solitary, acrogenous. 



Some twenty species. 



M. abrodens Nebr. is described as the cause of a very serious 

 grain disease in France. 



M. aductum Mas. injures Iris bulbs; 



M. allionun Berk, forms dark spots on onion. 



Septosporium Cda. (p. 616) 



Conidiophores short, intermixed with longer sterile hyphae; 

 conidia ovoid to pyrif orm, fuscous. 



A small genus. 



S. heterosporium E. & G. 



Spots scattered, confluent or not, rusty brown, 0.5-1 cm. in 

 diameter, conidiophores hypophyllous, fasciculate from the sto- 

 mata; conidia variable, oblong cylindric, constricted at the 

 septa, 20-40 x 5-7 n, separating into gemmse. 



Reported in 1888 ^* on the wild grape in California. 



