Orton : Correlation between Puccinia and Uromyces 201 



This discovery has led to the conclusion that the common form 

 has been responsible for the successful cultures upon Rihes of 

 this particular rust bearing the name P. albiperidia and that the 

 rust having urediniospores with one basal pore is an unconnected 

 form without a name. In order to discuss more readily this par- 

 ticular species I hereby propose the following name for it: 



Puccinia uniporula sp. nov. 



Urediniospores broadly ellipsoid, 16-23 by 25-29 /x, wall 1.5-2 

 thick, with only one pore placed near the hilum. Telia hypophyl- 

 lous, scattered, roundish or oblong, 0.2-0.7 mm. long, early naked, 

 pulvinate, dark cinnamon-brown. Teliospores broadly clavate, 

 15-20 by 34-48 fi, apex thickened up to 10 /x. Pedicel about once 

 the length of spore or less. 



The type is on Carex pubescens Muhl., collected at London, 

 Canada, August 20, 19 10, by J. Dearness. It has also been de- 

 tected on six other species of Carex, and occurs sparingly from 

 Newfoundland to Iowa. 



In 19 10, Dr. F. D. Kern^^ published the species Uromyces uni- 

 porulus on Carex tenuis, which has broadly ellipsoid uredinio- 

 spores measuring 18-21 by 21-26 /x, with cinnamon-brown walls 

 about 1.5 |U, thick, rather sparsely and distinctly echinulate, and 

 having one basal pore. The telial hosts of this rust are Carex 

 gracillima Schw. and C. tenuis Rudge, both of which are hosts 

 of Puccinia uniporula. The distribution of this species is now 

 known locally from the New England states to Wisconsin. The 

 aecial host of Uromyces uniporulus is unknown but it is undoubt- 

 edly the same as that of Puccinia uniporula. 



The rusts on Spartina have been studied considerably in the 

 past and three forms of Uromyces which variously intergrade 

 have been separated, having aecia on members of the Caryophyl- 

 laceae, Primitlaceae, and Polemoniaceae respectively.^^ The form 

 of Uromyces acuminatus Arth., having aecia on Steironema cilia- 

 tum (L.) Raf . and telia on Spartina gracilis Trin. and vS. Michaux- 

 iana Hitch, possesses urediniospores which are globoid, meas- 



^® Rhodora 12: 125. 1910. 



^Jour. Myc. 12: 24. 1906; 13: 193. 1907; 14: 17, 1908; Mycologia 2: 221. 

 1910 ; 4 : 29. 1912. 



