202 



MYCOLOGY 



repens, Elymus arenarius, Bromus secalinus and others; (3) f. sp. 

 avenm on oats and Avena elatior, Dactylis glomerata, Alopecurus praten- 

 sis, Milium efusum, etc.; (4) f. sp. pocB on Poa compressa and P. praten- 

 sis; (s) f . sp. airce on Aira cmspitosa and A . hottnica; (6) f . sp. agrosHs on 

 Agrostis canina and A. stolonifera. 



Brown Rust of Rye, Puccinia dispersa, with its cluster cups on 

 Anchusa arvensis and A. officinalis. 



Crown Rust of Oats, Puccinia coronifera, with its aecium on the 

 buckthorn, Rhamnus cathartica. Of this species there are eight 



Fig. 71. — A-C, Gymnoconia inlerstitialis. A, ^Slcidia on leaf of Rubus canadensis; 

 B. piece of leaf enlarged; C, teliospore; D, teliospore of Sphenospora pallida, 500/ i. 

 {After Dietel: Die natiirlichen Pflanzenfamilien I. lA**, p. 70.) 



speciahzed forms, as follows: (i) f. sp. avenee on oats; (2) f. sp. alope- 

 curi on Alopecurus pratensis; (3) f. sp. festuccB on Festucas; (4) f. sp. 

 lolii on rye grass, Lolium perenne; (5) f. sp. glyceriee on Glyceria aqua- 

 tica; (6) f. sp. agropyri on Agropyron repens; (7) f. sp. epigcei on Cala- 

 magrosHs epigeios; (8) f. sp. hold on Holcus lanatus. 



Crown Rust of Grasses, Puccinia coronata, with its aecium on Rham- 

 nus frangula. Three special forms of this rust are known: (i) f. sp. 

 calamagroslis on Calamagrostis arundinacea; (2) f. sp. phalaridis on 



'Arthur, J. C. and Kern, F. D.: North American Species of Peridermium. 

 Bull. Torr. Bot. Club, 33: 403-438, 1906. 



