408 FUNGOUS DISEASES OF PLANTS 



is one of the most common, yet it may not be considered of any 

 special economic importance. The aecidiospores are almost twice 

 as long as broad, 40 x 1 7-26 //,. The uredospores are subspherical, 

 and the teleutospores are conspicuous by their long, hyaline, and 

 relatively thick pedicels, papillate apex, red-brown color, and verru- 

 cose outer wall. 





FIG. 200. ^CIDIAL STAGE OF THE GRAIN RUST ON BARBERRY 



XIII. BLACK RUST OF GRAIN 

 Pucrinia graminis Pers. 



BOLLEY, H. L., and PRITCHARD, F. J. Rust Problems. N. Dak. Agl. Exp. 



Sta. Built. 68: 607-672. figs. 1-30. 1906. 

 CARLETON, M. A. Cereal Rusts of the United States. Div. Veg. Phys. and 



Path., U. S. Dept. Agl. Built. 16: 1-73. pis. 1-4. 1899. 

 DE BARY, A. Neue Unters. iiber die Uredineen, insb. d. Entw. der Puccinia 



graminis u. d. Zusammenhang desselben mit Aecidium Berberidis. Monats- 



ber. K. Akad. d. Univ. Berlin (1865): 15-49. pi. n. 

 ERIKSSON, J. Neue Unters. iiber d. specialisirung Verbreitung u. Herkunft 



des Schwarzrostes (Puccinia graminis Pers.) Jahrb. f. wiss. Bot. 29 : 



499-524. 1896. 



ERIKSSON, J., und HENNING, E. Die Getreideroste, /. c. 

 McALPiNE, D. The Life-history of the Rust of Wheat. Dept. Agl. Victoria 



Built. 14: 1891. 

 OLIVE, E. W. Rusts of Cereals. S. Dak. Agl. Exp. Sta. Built. 109: 1-20. 



figs. 1-5. 1908. 



WARD, H. MARSHALL. Illustrations of the Structure and Life-history of Puc- 

 cinia graminis, the fungus causing the " Rust " of Wheat. Ann. Bot. 2 : 



217-222. fits. //, 12. 1 8$8, 



