a 



CULTURES OF UREDINE& IN i8gg f^oo 



II. PUCCINIA PERIDERMIOSPORA (E . & T.) Artk. 



In studying the grass rusts it was noticed that a form on 

 Spartina, well represented in American herbaria and usually- 

 called Puccinia Phragmitis, had uredospores similar to those of 

 Puccinia Vilfce, just described. I searched through my collec- 

 tion of iEcidia to see if any species with corresponding apically 

 thickened spores could be found, and was rewarded in the case 

 of Alcidium Fraxini Schw. With this morphological hint as the 

 sole guide cultures were undertaken. 



Spartina does not grow within many miles of Lafayette, and 

 I am indebted to the kindness of Professor C. E. Bessey, of Lin- 

 coln, Neb., and Mr. H. H. Hume, of Ames, Iowa, for teleuto- 

 sporic material upon Spartina cynosuroides. The teleutospores 

 germinated with marked vigor, and were first sown on Ptelea 

 trifoliata, the small plants obtained being mistaken for Fraxi- 

 nus. When the mistake was discovered, and sowings were made 

 on Fraxinus viridis, infections were first secured. As no small 

 plants of Fraxinus were available, the spores were sown upon 

 cut twigs placed in water in the greenhouse, and upon a low 

 branch of a large tree out of doors. There could be no fear of 

 spontaneous infection, as the species does not occur in the 

 region, either upon Spartina or Fraxinus, but the usual precau- 

 tions were taken. The sowings were both successful. The dates- 

 are as follows : 



May 8, Teleutospores (Neb.) sown on Ptelea trifoliata ; no infection. 

 May 9, Teleutospores (Neb.) sown on Ptelea trifoliata ; no infection. 

 May 9, Teleutospores (Iowa) sown on Ptelea trifoliata ; no infection. 

 May 15, Teleutospores ^Neb.) sown on Ptelea trifoliata; no infection. 

 May 17, Teleutospores (Iowa) sown on cut twigs of Fraxinus viridis ; May 



24, spermogonia ; June 6, aecidia. 

 May 17, Teleutospores (Neb.) sown on tree out of doors of Fraxinus viridis ; 



May 29, spermogonia; June 8, aecidia. 



SUMMARY. 



The following are the eleven species of Uredineae, whose 

 aecidial and teleutosporic forms have been definitely connected 

 by cultures : 



