222 THE ASCOMYCETES 



Gnomonia leptostyla produces bacillar spermatia in acervuli con- 

 currently with the conidial stage, Marssoiiia jiiglmidis. 



Klebahn (1905) first connected a Gloeosporium with Gno- 

 monia in his study of the sycamore-blight pathogen. The conid- 

 ial stage, causing the buds to blight and necrotizing strips on 

 either side of the veins of older leaves, is known as Gloeosporimn 

 nerviseqinim. The stage blighting the twigs is known as Myxo- 

 sporiimi valsoideiim. On fallen leaves cleistocarpous pycnidia 

 are produced and are known as Sporonema platani. This last- 

 named stage may prove to be spermogonial. Klebahn listed six- 

 teen names in synonvmy of Gnovwma veneta, and Edgerton 

 (1908) added two others. The sycamore-blight pathogen grown 

 on oaks, which Stoneman (1898) and Edgerton (1908) regarded 

 as hosts, has much longer perithecial beaks than when it is grown 

 on sycamore. 



Stoneman (1898) determined that Gloeosporium cingiilatinn 

 occurring on privet has a perithecial stage for which she em- 

 ployed the generic name Gnomoniopsis. Von Schrenck and 

 Spaulding (1903), in connection with studies on apple bitter rot, 

 found that the perithecial stage occurs on limb cankers and on 

 decaying fruits. They found furthermore that the apple pathogen 

 belongs in the Genus Gnomoniopsis, as described by Stoneman, 

 but, because of preoccupation of Gnomoniopsis, they established 

 in its stead the Genus Glomerella. Some regard the organism on 

 privet and that on apple as specifically identical; support for this 

 belief comes from extensive studies by Shear and Wood (1913). 

 They found it on avocado, cinnamon, coffee, cocoa, cranberry, 

 dewberry, ebony, fig, grape, guava, loquat, mango, and tea. 

 Other workers contend that species of Glomerella have greater 

 host specificity than is indicated by Shear and Wood's studies. 



Edgerton (1914) secured evidence of heterothallism in strains 

 of Glomerella, isolated from Fopiihis deltoides and Ipomoea pur- 

 purea. These isolates appeared indistinguishable from the apple- 

 bitter-rot fungus. By mating strains he secured rows of perithe- 

 cia on the boundary Hne between colonies cultured in Petri 

 dishes. 



The perithecial stage of certain species of Glomerella has never 

 been observed except on host tissues. Others, however, such as 

 the bean-anthracnose fungus and the watermelon-anthracnose 

 fungus, appear never to have been observed except in artificial 



