371 



122. Uromyces SEDITIOSUS Kern, Torreya 11:212. 1911. 



Aecidinm Plantaginis Burrill, Bull. 111. Lab. Nat. Hist. 2:232.' 1885. 



Nigredo seditiosa Arth. N. Am. Flora 7:225. 1912. 

 On Poaceae: 



Aristida sp., Lewes, 1908. 



Culture experiments reported by Arthur (Bot. Gaz. 35:17. 1903) 

 prove the aecidial stage of Uromyces Aristidae to be Aecidium Planta- 

 ginis. He used telial material on A. oligantha Michx. from Texas and 

 successful infection of Plant ago Rugelii was obtained followed by pycnia 

 and aecia. 



Field observations made by Arthur and Frcmme indicate also that 

 Aecidium Oldenlandianum Ellis & Tracy, which occurs on various spe- 

 cies of Houstonia in the southern states, also belongs here though con- 

 firming cultures have not yet been made. 



123. Uromyces Silphii (Burrill) Arth. Jour. Myc. 13:202. 1907. 

 Aecidium Silphii Sydow, Ured. 1546. 1901. 



Nigredo Silphii Arth. N. Am. Flora 7:239. 1912. 

 On Juncaceae: 



Jxincus dichotomus Ell., Sussex Co., June 18, 1875, A. Commons. 



Juncus tenuis Willd., Lewes, Aug. 14, 1907, (1700) ; Newark, 



Aug. 23, 1907, (1714); Sept. 1907, (1823, 1824); Selbyville, 



Oct. 4, 1907, (1793, 1800). 



Arthur (Jour. Myc. 13:202. 1907; 14:17. 1908) has shown that 



this common species has its aecia on Silphium. Using telial material on 



J. tenuis from Indiana, West Virginia and Nebraska, five successful 



infections of Silphium perfoliatum were obtained, all of which resulted 



in the development of pycnia and aecia. The aecia on Silphium have 



been collected, so far as known to the writer, only in the Mississippi 



Valley from Ohio to Wisconsin, Kansas and Missouri, on three species 



of Silphium. The range of the telial collections referred here, however, 



is much greater including nearly the entire United States and Canada 



except the south Pacific slope. It seems probable that some plants other 



than Silphium, at present unrecognized, also serve as aecial hosts for 



this species. From field observations it seems probable that certain 



species of Aster .serve as hosts for the aecia of this species in some 



localities. 



