254 FUNGOUS DISEASES OF PLANTS 



A. No stroma present; perithecia for the most part completely immersed 



in the substratum, or finally becoming more or less free by the rup- 

 ture of the inclosing matrix (epidermis in the parasitic forms). 



i . Perithecia for the most part without distinct beak, tough but 

 not carbonaceous. 



a. Asci arising in groups from the perithecial wall with- 



out intervening paraphyses . Mycosphczrellacecz 

 (Represented by Gitignardia and Mycosphcerella.) 



b. Asci arising from the base of the perithecium and 



not in groups. Paraphyses present. Pleosporacea 

 (Represented by Venturia.) 

 2. Perithecia carbonaceous or tough leathery, as a rule with 

 a distinct beak. Asci thickened at the apex, commonly 



breaking open by a pore Gnomoniacece 



(Represented by the genera Glomerella and G7iomonia.) 



B. No stroma present ; perithecia free upon the substratum, or surrounded 



at the base by a dense mycelial mat Sphczriacetz 



(Represented by Rosellinia.) 



C. Stroma present, consisting of intermixed and modified fungous and host 



elements ; perithecia imbedded ; pycnidia present . . . Valsacea 

 (Represented by Diaporthe.) 



D. Stroma present, consisting of fungous hyphse only ; perithecia im- 



mersed Xylariacece 



(Represented by Nummularia.) 



XL. BLACK ROT OF GRAPES 

 Guignardia Bidwellii (Ell.) Viala & Ravaz 



Edson, A. W. The Black Rot of the Grape in North Carolina and Its Treat- 

 ment. N. C. Agl. Exp. Sta. Built. 185: 131-150. 1903. 



Jaczewski, A. V. Uber die Pilze, welche die Krankheit der Weinreben 

 "Black Rot" verursachen. Zeitsch. f. Pflanzenkr. 10: 257-267. figs. 

 1-8. 1900. 



Reddick, D. The Black-Rot of the Grape and Its Control. Cornell Univ. 

 Agl. Exp. Sta. Built. 253: 367-388. Jigs. 177-187. 1908. 



Report on Experiments made in 1888 in the Treatment of the Downy Mil- 

 dew and Black Rot of the Grape Vine. U. S. Dept. Agl. Bot. Div. 

 Built. 10: I -61. 1889. 



Scribner, F. L. The Fungous Diseases of the Grape Vine. Bot. Div. U. S. 

 Dept. Agl. Built. 2 : 28-34. ///. 1886. 



Scribner, F. L. Fungous Diseases of the Grape and Other Plants and their 

 Treatment. 1890. 



Viala, P. Les maladies de la vigne. 59s pp. iq pis. 2gofigs. (Black Rot: 

 156-203. pi. 4. figs. 48-34.) 1893. Montpellier et Paris. 



Viala, P., et Ferrouillat, P. Manuel pratique pour le traitement des mal- 

 adies de la vigne. 1888. 



