228 



Arthur: Cultures of Uredineae 69 



no absolute difference between the types of P. albiperidia and P. 

 uniporula. But P. albiperidia has been cultured on Ribes, pro- 

 ducing aecia that can not be distinguished from those Carex rusts 

 which show urediniospores with equatorial pores only. Whether 

 aeciospores grown from P. albiperidia material would reproduce 

 urediniospores, when sown back on a suitable Carex, with only 

 three-pored or only one-pored urediniospores, or with sori con- 

 taining a mixture of the two, is yet to be demonstrated. In the 

 meantime, it seems best to use the name P. albiperidia as represent- 

 ing a form with aecia on Ribes, and synonymous with P. Grossu- 

 lariae, while P. uniponda can be retained for such collections as 

 show a preponderence of one-pored urediniospores. It is inter- 

 esting to note in this connection that in Europe no Carex rust 

 has yet been found agreeing with the uniporulate forms here 

 discussed. 



The essential specific unity of all Carex-Ribes rusts in both 

 America and Europe was the conclusion reached by Dr. H. Kle- 

 bahn in 1907. Dr. Klebahn's extended cultural work on this 

 group of rusts began in 1892, and resulted in the separation of 

 five species. In 1904 and 1906 he studied the behavior of Amer- 

 ican material grown from teliospores transmitted by the writer. 

 Taking into account both European and American material, he 

 came to the conclusion 9 that the six described species of Carex- 

 Ribes rusts were biological forms of one collective species, for 

 which he suggested the name, Puccinia Ribesii-Caricis. This 

 conclusion is upheld by the above study, although an earlier name 

 is preferred for the species. 



2. Puccinia Caricis-Asteris Arth. (P. Carick-Solidaginis 

 Arth.) Five successful cultures of this rust were secured. They 

 are as follows : 



Teliospores from Carex sp., London, Ontario, sown April 10 on Aster sp., 



showing pyenia April 16, and aecia April 27. 

 Teliospores from Carex sp., Lafayette, Ind., sown April 1 1 on Aster sp., 



showing pyenia April 23, and aecia April 29. 

 Teliospores from Carex retrorsa, St. Anne de Bellevue, Quebec, sown May 



14 on Aster paniculatus, showing pyenia May 22, and aecia May 27. 

 Teliospores from Carex scoparia, St. Anne de Bellevue, Quebec, sown 



May 13 on Aster paniculatus, showing pyenia May 22, and aecia 



8 Klebahn, Zeits. Pflanzenkr. 3: 134. 1907. 



