Arthur: Cultures of Uredineae in 1915 135 
proved to be F. 5" and the aecia on resembled 
those belonging to that species. Mr. Latham kindly sent viable 
material for cultures, collected at the same spot June 2, 1915, 
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 
Chenopodium album. Pycnia began to show April 25, and aecia 
May 8, chiefly on the petioles of the leaves.^® 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 Dirca palustris, 
beginning with the illusory success of 1903 and continuing to the 
present time.^^ Many telial collections have been used, secured 
from widely separated localities, and 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. 
IT 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, 1 1, 12. 1912 ; 7 : 64, 65. 1914. 
