26i 



Arthur: Cultures of Uredineae in 19$ 13*3 



difficult to locate this rust in localities from which culture ma- 

 terial could be secured. Dr. Brenckle sent material from Kulm, 

 N. Dak., from which cultures were attempted in 1909 and 1910" 

 upon a score of different hosts, but not including Steironema. 

 Again material on S. Michauxiana was obtained from Dr. 

 Brenckle, collected April 8, 1915, at Kulm, N. Dak., and also from 

 Rev. J. M. Bates, collected April 20, 191 5, at Loup City, Neb. 



The North Dakota material was sown May 8, on Steironema 

 ciliatum, and pyenia began to show May 16, followed by an 

 abundance of aecia May 22. ' The Nebraska material was sown 

 May 8, on Steironema ciliatum and Polemonium reptans. The 

 Polcmonium plant remained uninfected, but many pyenia began 

 to show on the Steironema May 14, followed by a great abundance 

 of aecia May 20. Although these cultures were exceedingly vig- 

 orous and in so far seemed beyond question, yet there exists a 

 possible small source of error. The correlated Uromyces is a 

 common rust, and occasionally grows upon the same leaves with 

 the Puccinia. In the Nebraska material no admixture could be 

 found, but there were sori of Uromyces on the North Dakota ma- 

 terial. Care was exercised, however, to avoid all sori with one- 

 celled spores in making the cultures, and as the two forms were 

 mostly on separate leaves, there is little reason to doubt that the 

 cultures were pure. Correctness of the general conclusion was 

 obtained from a wholly independent source, however, when Dr. 

 Brenckle sent a collection of aecia on Steironema ciliatum, made 

 by Prof. O. A. Stevens near Fargo, N. Dak., May 23, 191 5. On 

 June 5 Dr. Brenckle accompanied Prof. Stevens to the spot where 

 the collection was made, to institute a search for Spartina, as Prof. 

 Stevens had reported that the grass did not grow within miles of 

 the place. Dr. Brenckle writes, June 16, that he " found a small 

 isolated bunch of Spartina in the midst of the infected spot; 

 the rust on the Spartina was Puccinia! " The collection of aecia 

 has been issued as Fungi Dakotenses j/d, under the name of 

 Puccinia Distichlidis. This is the only field collection of aecia 

 positively known to belong to the Puccinia form. 



3. Puccinia montanensis Ellis. There has been much con- 



-"- Mycol. 2 : 219. 1910; 4:11. 1912. 



