THE FUNGI WHICH CAUSE PLANT DISEASE 649 



F. gemmiperda Aderh. is described by Aderliold "" as fatal to 

 flower buds of cherry before they open, a conclusion supported by 

 inoculation experiments. The disease in general appearance re- 

 sembles sclerotiniose. 



F. rhizogenum P. & C. 



Sporodochia superficial, 1 to 2 mm. wide, dense, convex, white 

 or whitish, hyphse densely interwoven, septate, subramose; conidia 

 oblong, roundish, 1-septate, 70 x 4 /«. 



It was originally described as a parasite on apple roots in Ne- 

 braska '" and is mentioned by Aderhold ^ as the cause of death of 

 roots of apple and cherry trees in Europe. The mycelium grows 

 within the roots and gummosis of the wood occurs. A Cephalo- 

 sporium form is known, also chlamydospores. 



F. putrefaciens Osterw.'^^'"^ is said by Osterwalder "* to cause 

 decay of pomaceous fruits. 



F. cubense E. F. Sm. was isolated from bananas affected with 

 blight. Inoculation showed the fungus capable of growing through 

 the bundles for long distances.'™ 



F. limonis Bri.™ »"• ^^ 



Sporodochia gregarious, confluent, white; hyphse spreading, 

 branched, septate; conidiophores erect, with alternate or opposite 

 branches; conidia variable, acrogenous, continuous to 3-septate, 

 oblong to fusiform, curved, pointed, slightly constricted, 26-27 x 

 2.4-2.8 fi. 



This fungus is held to be contributory to, if not responsible for, 

 the Mal-di-gomma or foot-rot of citrous 

 fruits which is knoAvn practically wherever 

 these fruits are cultivated. 



F. culmorum (W. Sm.) Sacc.^*' ^^ 



Reddish-yellow, gelatinous, effuse; h3rphae 

 few-septate, tortuous; fertile, short, con- 

 tinuous; conidia fusoid-falcate, 3 to 5-sep- 

 tate, 28-32 x 6-8 fi on wheat. Fiq. 438.— f. culmorum. 



The fungus affects chaff and seed, first ^*^' ^''^'*"- 



appearing as a whitening of the upper halves of the glumes fol- 

 lowed later by a pink color. The glumes become cemented to- 

 gether and the whole head may be involved. The grains are of 

 light weight and are often covered with the fungus. Chester 



