386 



THE KCSTS OF NOVA SCOTIA. — KKASEH. 



This species was for some time confused with Phr. 

 suhcorticium (Sehrnk) Wint. {Plir. mucronatum Lk.). Peck 

 first called attention to a variation in the- 

 number of cells. He states that ''American 

 specimens generally have the spores more 

 opaque and with two or more septa than 

 the typical form. This variant form 

 might be called Var. arnericanum." (N. 

 Y. State Mus. Rop. 28: 86). Dietel raised 

 the variety to specific rank under the 

 name of Phr. amc.rlcanum. 



According to Arthur Phr. nrnericanum 

 inhabits the north-eastern region of North 

 America along the Atlantic coast from 

 Maryland northward and north of the 

 great lakes, chiefly on llosa blanda, R. 

 Incida, R. Sayl and certain cultivated 

 varieties derived from these (Torreya 

 »:27. 1909). 



It seems to be common on the roses in this vicinity, (/ol- 

 lections of another stage of the rust were made but they were 

 lost in drying. The collection reported in Dr. MacKay's 

 Fungi of K S. (Trans. K S. Inst, of Science 12:124) as 

 Phr. suhcorticium belongs here. 



Phragmidium imitans Arth. 



Phragmidium gracile Arth. 



0. Pyonia not observed. 



1. Aecia rounded, small, scattereil, ej)ij)hyllou';, s{K)n 

 naked, yellowish. Aeciospores rounded, oblong, elliptical or 

 oval, 16-24 by 12-29/x; wall unequally thickened, echinulate; 

 paraphyses slend<'r, long, clavate, hyaline, inruvved. 



II. TJredinia hypophyllous, scattered, small, rounded. 

 Urediniospores elliptical or obovate, 12-10 by 20-24^; wall 

 rather thick, colourless, echinulate; paraphyses slender, clavate, 

 thin-walled, hyaline, al:)Out 13-22 by .5r)-80M, incurved. 



TelioHpores of Phragmid 

 ium arnericanum. 



