74 
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 Pucciitia fomipara Trek, 
was grown on Clematis virginiana. In a discussion of the re- 
sults^® 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®® 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 tlie western form, but distinct from the eastern Bromus- 
Clcmatis rust. 
In 1908 a rust on Bromus from the Rocky ^fountains 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.^^ 
The first cultural study of this group of subepidermal rusts 
began in 1903 with a supposed culture of Dirca aecia on Bromus,"^ 
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 
i»Jour. Myc. ii : 62—63. 1905; also 13; 197. 1907; and Mycol. i: 236. 
1909. 
20 Jour. Myc. 14: 15. 1908. 
21 Mycol. i; 248-231. 1909; also 2: 223. 1910. 
22 Jour. Myc. 10: 19. 1904; also ii : 62. 1905. 
