PHRAGMIDIUM. 



363 



On species of Potentilla : 



Phr. fragariastri (D. C.) (Britain and U.S. America). 



Phr. potentiUae (Pers.) (U.S. America). 



Phr. tormentillae Fuck. (Britain.) 



Phr. papillatum Dietel, from Siberia. 



Phr. nepalense Barcl. and Phr. laceianum Barcl. in India. 



On species of Bubus : 



Phr. rubi (Pers.) {Phr. bulbosum 

 Schlecht.) (Britain). 



Phr. rubi-idaei (Pers.). On leaves 

 of raspberry. (Britain and U.S. 

 America.) 



Phr. violaceum (Schultz) (Britain). 



Phr. rubi-miniatum J. Miill. 



Phr. albidum (Kiihn). 



Phr. quinqueloculare Barcl. 



Phr. octoloculare Barcl. 



Phr. Barclayi Dietel, from Hima- 

 laya. 



Phr. gracile Pari., America. 



And other species. 



On Sanguisorba : 

 Phr. san^isorbae (D. C). On 

 Sanguisorba minor. (Britain.) 



Phr. carbonarium (Schlecht.) 

 (Britain). This species has also 

 been placed in a separate genus 

 Xenodochus. It occurs on San- 

 guisorba. TJredospores are want- 

 ing ; the teleutospores form firm 

 black crusts ; the aecidiospores 

 form chains ; and the paraphyses 



are club-shaped. Diseased leaves and petioles are thickened and 

 bent. Wakker's investigation showed: a slight enlargement of 

 parenchymatous cells and rupture of epidermis on spore-formation ; 

 a diminution in the intercellular spaces and in formation of 

 collenchyma and sclerenchyma ; a suppression of all production 

 of chlorophyll and calcium oxalate. 



Fig. 195. — Phragmidium rubi from Ruhus 

 iruticosus. One spherical immature te- 

 leutospore, and two well-developed and 

 germinating ones. (After Tulasne.) 



Melampsora. 



Teleutospores dark and unicellular, in some cases multi- 

 cellular by formation of new walls, generally in a vertical 



