74 Ov Mycologia 



Cultures from Elymus on Clematis ligusticifolia are now re- 

 ported for the first time. It has seemed quite probable from field 

 observations that the aecia occurring on this host in great abun- 

 dance throughout the Rocky Mountains were probably connected 

 with telia on other hosts than Agropyron, where they have usually 

 been assigned in this country and Europe, but this is the first 

 direct proof by cultures. In 1904 a rust on Bromus from Iowa, 

 Indiana, and Wisconsin, believed to be Puccinia tomipara Trel., 

 was grown on Clematis virginiana. In a discussion of the re- 

 sults 19 it was considered that the aecia were the form known as 

 Aecid. Clematitis Schw., and distinct from the form in the Rocky 

 Mountains, going to telia on Agropyron. The latter form, called 

 Aecid. Clematidis DC, was grown in 1907 20 from Rocky Moun- 

 tain material on Agropyron, but on the eastern host C. virginiana, 

 no plants of C. ligusticifolia being available at the time. This 

 was considered a demonstration that the form known and cul- 

 tured in Europe as P. Agropyri E. & E., on Agropyron, is identi- 

 cal with the western form, but distinct from the eastern Bromus- 

 Clematis rust. 



In 1908 a rust on Bromus from the Rocky Mountains was 

 grown on Thalictrum dioicum with success. The same season a 

 similar subepidermal rust on Agropyron from the western moun- 

 tains was grown on Aquilegia. These two forms were considered 

 to represent distinct species and were named respectively Puc- 

 cinia alternans and P. obliterata. 21 



The first cultural study of this group of subepidermal rusts 

 began in 1903 with a supposed culture of Dirca aecia on Bromus, 2 * 

 an error which was rectified in the report of cultures the year fol- 

 lowing. From that time to the present morphological studies, 

 field observations, and careful cultures have multiplied until now 

 there seems to be no further doubt that this group of subepidermal 

 forms, passing under various names, represents only one species, 

 but a species broken up into a number of races of considerable 



19 Jour. Myc. n : 62-63. 1905; also 13: 197. 1907; and Mycol. 1: 236. 

 1909. 



20 Jour. Myc. 14: 15. 1908. 



21 Mycol. 1: 248-251. 1909; also 2: 225. 1910. 



22 Jour. Myc. 10: 19. 1904; also 11: 62. 1905. 





