514 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Conidia muticate 3. Stagonospora, p. 514. 



Subicle present, dark, phyllogenous 4. Asterostomidium. 



Pycnidia elongate to cylindric 5. Mastomyces, p. 514. 



Stagonospora Saccardo 

 ^ Pycnidia superficial or erumpent, 



c^<^^^r^ _ globose, ostiolate-papillate, black, 

 "^ membranous or subcarbonous; co- 



nidia elongate, 3 or more-celled. 

 Over one hundred species, chiefly 

 ^ saprophytes; differing from Hen- 



'^^^ '^\ r^ dersonia only in the hyaline conidia. 

 ^^\ (^Q^^^^^ S. carpathica Bseuml. 



^^^ '^^^ Spots circular, 1-3 mm., light 



brown with a narrow darker border; 



Fio. 355. — Stagonospora. C, pyc- -j- iorv ion ■ i- 



nidium in section. D, spores, pycnidia 120-180 (i] comdia escapmg 

 After Corda. -^^ ^ gelatinous mass, straight or 



slightly curved, 14-28 x 4 ju, 2 to 5-celled, frequently slightly 



constricted.'' It causes leaf spots on alfalfa. 

 S. iridis Mass. occurs on iris. 



Mastomyces Mont. 



Pycnidia gregarious, separate, erumpent, elongate, papillate- 

 ostiolate; conidia fusiform, 3-septate. 



There are two species, one of which, M. friesii Mont., is 

 probably the conidial form of Scleroderris ribesia, see p. 155, the 

 cause of a relatively unimportant currant disease of Europe. 



Sphaerioidacese-Phaeophragmise (p. 480) 

 Conidia hyaline, 2 to several-septate, oblong to f usoid. 



Key to Genera of Sphserioidaces-Phseophragmis 



Pycnidia separate 

 Pycnidia not beaked 

 Conidia free from each other 

 Conidia muticate 

 Pycnidia papillate or subastomous 



Pycnidia with flattened base 1. Macrobatis. 



