370 UREDINEAE. 



M. ariae (Schleich.). On leaves of Pyrus aria. 



M. padi (Kiinze et Schum.). On leaves of Prumis Padvs. (Britain.) 



M. hypericorum (D.C). On Hypericum. (Britain.) 



M. pustiilata (Pers.). On Epilohium. (Britain and U.S. America.) 



M. circaeae (Sclmiu.). On Circaea. (Britain.) 



M. vaccinii (Alb. et Sclim.). On leaves of Vacciniwn. (Britain and U.S. 

 America.) 



M. pirolae (Gmel.). On Pyrola. (Britain and I^.S. America.) 



M. sparsa Wint. (U.S. America). On Arctost(iphyh).'< alpina (also A. 

 officinalis ace. to Rostrup). 



M. carpini (Nees.). On leaves of hornbeam. 



M. galii (Lk.). On Galium. 



M. (Thecopsora) agrimoniae (D.C) On Agrimnnia. 



M. vernalis Niessl. Teleutosporcs only on Sa.vifraga granvlata. 



M. helioscopiae (Pers.). On Euphorbia. (Britain.) 



M. euphorbiae-dulcis Otth. 



Melampsorella. 



The unicellular teleutospores are developed in the cells of 

 the epidermis and form reddish patches. The patches of 

 uredospores are enclosed in a peridium. 



Melampsorella cerastii (Pers.). Uredo- and telentospores on species of 

 Stellaria and Cerastiv.m. (Britain and U.S. America.) 



Calyptospora. 



The teleutospores are developed inside the epidermal cells, 

 and are divided into four cells by vertical septa. The aecidia 

 have large peridia. The pycnidia are small and precede the 

 aecidia. 



Calyptospora Goeppertiana Kiihn.i (U.S. America). The 

 common disease of cowberr}- {Vaccininm Vitis-ldaca) caused by 

 this parasite is shown externally by a very marked swelling 

 and elongation of the shoots (Fig. 202). Diseased plants 

 elongate conspicuously above their neighbours, and in this way 

 distribution of their spores by wind is facilitated. The mycelium 

 hibernates in the cortical tissues, and maintains itself for years. 

 It grows intercellularly, sending haustoria into the cortical cells. 

 As a result of its presence, cell-growth is much accelerated, 

 and a marked tliickening of attacked twigs frequently occurs ; 



'R. Hartig, Lehrlmrh d. Baumh-ankheitev , i. Aufl. p. SO and PI. II. (The 

 2nd edition and tlic English translation are sonieMhat abridged.) 



