DESCRIPTION OF AMERICAN UREDINE.E. 57- 



Sori at first reddish brown, then grey from the germinating 

 spores, round, pulvinate, mostly thickly covering the under- 

 side of the leaf; spores oblong, constricted, apex mostly 

 rounded, thickened 6-8,u ; epispore bi'own, smooth, 16-20// 

 by 32-44„ ; pedicels persistent, hyaline up to loo/^ long, 6-8." 

 wide. Plate III., Figs. 17a, 17b. 



The apex of spores that have germinated, is occasionally torn 

 so as to leave a few projections, somewhat resembling the 

 processes on the spores of Puccinia coronata. 



Dr. Dietel has compared specimens of this species collected 

 in California by L. B. Parish on Arabis holbcellii with the 

 original specimens from Greenland and found them identical. 



Some of Mr. Parish's specimens were accompanied by an 

 ^'Ecidiuni, which probably has no connection with this species.. 



The specimens 17a and 17b were collected on the same 

 plants, the latter being on older stems, which were quite dry 

 and dead. 



As stated in the quotation above from F^iingi Grociil. the 

 original specimens described as ^^cidiiuji holboellii Horn, were 

 found by Rostrup to have no trace of an ^"Ecidiuiu — only this 

 Leptopuccinia. 



It is different from Piicciiiia Ihlaspeos Schub. which Ros- 

 trup at first thought was perhaps a synomym. 



