259 



Arthur: Cultures of Uredineae in 135 



proved to be P. Seymouriana, and the aecia on Asclepias resembled 

 those belonging to that species. Mr. Latham kindly sent viable 

 material for cultures, collected at the same spot June 2, 191 5, 

 which was sown June 10 on plants of the four hosts used in the 

 previous culture. Only Asclepias syriaca became infected, show- 

 ing an abundance of pycnia June 17 and great numbers of aecia 

 June 23. 



It may fairly be concluded that this species of rust is one com- 

 posed of well-marked races in accordance with the aecial hosts. 

 Besides the three races here indicated, another doubtless occurs 

 in connection with Amsonia, the characteristic aecia having been 

 found on this host from Missouri. 



7. Puccinia subnitens Diet. A collection of this rust on 

 Distichlis spicata, very common in alkaline regions, was sent by 

 Prof. H. S. Jackson from LaGrand, Ore., and sown April 15, on 

 Chcnopodium album. Pycnia began to show April 25, and aecia 

 May 8, chiefly on the petioles of the leaves. 16 Telial material 

 has now been cultured from the states of Nebraska, Colorado, 

 Delaware, Nevada, and Oregon, extending from the Atlantic to 

 the Pacific coasts. 



8. Puccinia Windsoriae Schw. Much attention has been 

 given to finding the telial host for the aecia on Dire a palustris, 

 beginning with the illusory success of 1903 and continuing to the 

 present time. 17 Many telial collections have been used, secured 

 from widely separated localities, arid representing many species 

 of rusts. During the last year a search through the herbarium 

 for aecia on other hosts, having similar microscopic characters, 

 led to the possibility that it might be a racial part of the common 

 Puccinia Windsoriae. To test this hypothesis telial material was 

 secured near Lafayette, on Tridens flavus, from the vicinity of 

 Dirca bushes, annually showing the lemon-yellow spots carrying 

 the aecia. Sowings were made May 3, on Dirca palustris, May 



16 For previous cultures see Bot. Gaz. 35:19. 1903; Jour. Myc. 11:54. 

 1905; 12:16. 1906; 13:197. 1907; 14:15. 1908; Mycol. 1:234. 1909; 

 2:225. 1910; and 4: 18, 54. 1912. 



17 For previous attempts see Jour. Myc. 10: 19. 1904; 11:56. 1905; 13: 

 191, 192, 196. 1907; 14: 12. 1908. Mycol. 1:231. 1909; 2:219, 227. 1910; 

 4:9, 10, 11, 12. 1912; 7:64, 65. 1914. 



