THE FUNGI WHICH CAUSE PLANT DISEASE 



605 



conidia elliptic-oblong, 1-septate, translucent, tawny, 10-20 x 4- 

 6m. 



The hyphse are abundant on the lower sides of tomato leaves, 

 forming a mold, varying from whitish to purplish in color. 



It causes serious disease in Europe and America. 



C. condylonema Pass, is found on leaves of Prunus causing leaf 

 spot and curl. 



C. bigarardia is on Citrus. 



C. macrocarpum Preu.^ 



Subeffuse, black; conidiophores subfasciculate, simple, some- 



FiG. 407.— C. fulvum. After Southworth. 



what flexuose, brown; conidia oblong, oblong-ovate, 2 to several 

 septate, obtuse, pale brown. 



On spinach leaves in New Jersey, causing disease. 



C. graminum Cda. 



Clusters minute, irregular, scattered, greyish-brown; conidio- 

 phores distinct, erect, simple, nodulose-flexuose, brown; co- 

 nidia concolorous, continuous to several-celled, rounded or 



oblong. 



It is reported that this fungus was commonly present on sterile 

 wheat florets and that inoculation with it increased such sterility 

 slightly. 



C. oryzae S. & Sy. is on rice; 



C. orchidis C. & M. on Oncidium; 



C. pisi Cu. & Ma. on Pisum. 



