74 Journal of the Mitchell Society [Septemher 



of vetch from any other of the diseases of this plant. Young lesions 

 are at first manifest as irregular purplish diseolorations. The middle 

 line of these discolored areas becomes whitish following the rupture 

 of the epidermis by the acervulus or fruit-body of the fungus, Fig. 27. 

 The mass of spores which comes out may give to the center of the 

 spot a pale pink or salmon color. With age, the whitish portions of 

 the lesions become black and the purplish halo disappears as the 

 pods become dry. Mature lesions appear as black, elliptical or elon- 

 gated oblique spots. Fig. 28, their direction being no doubt due to 

 the oblique fibrous structure of the pod. 



Etiology 



False anthracnose is caused by an organism, Protocoronospora 

 nigricans, which was described, in 1907, l\y Atkinson and Edgerton 

 as the type of a new genus. Since, during the writer's studies, this 

 fungus was found to possess certain characters, to be described later 

 in this report, which are common to the true anthracnoses, compari- 

 son was made with the several species of Gloeosporium occurring on 

 vetch. Specimens of the two American species, Gloeosporium Davisii 

 E. et E. and G. Everhartii Sacc. et Syd., which occur on the legumes 

 and on the leaves respectively of Vicia autericana were loaned through 

 the courtesy of Dr. J. J. Davis, Madison, Wisconsin, by whom they 

 were first collected. The latter species was first described as G. ameri- 

 canut)! E. et E^., a combination which had been earlier employed for 

 a fungus occurring on Aranja olhens (described from Argentina l)y 

 Spegazzini in Fungi Arg. Pug. II,, p. 36). Even tliough these two 

 species differ in size of conidia, they will probably be found to be iden- 

 tical when submitted to cultural and inoculation tests. Certainly 

 they are distinct from the organism under consideration. 



A form which occurs on stems of Vicia cracca in France and was 

 described^ as G. viciae Fautrey et Roum. is also very different and 

 beyond doubt is identical with Myxosporium viciae Fautrey. There 

 is furthermore no chance of confusing Protocoronospora nigricans 

 with G. tricolor Lind which produces a "frog-eye" leafspot disease of 

 Vicia cracca in Denmark.^ 



sProc. Acad. Nat. Sci. Phila., 1893, p. 1C7. 



* Fungi exsiccati precipue Oallici Centiirie LV. Revue MvcoIogi<iue annee 12, 1890, 

 p. 168. 



i^Annales Mycol. 5: p. 277, 1907. 



