Arthur: Cultures of Uredineae in 1915 
129 
grass rusts has shown the probability that this form, usually re- 
ported under the name P. ruhigo-vera, is a part of the compre- 
hensive species, P. Agropyri, with aecia on different Ranuncula- 
ceous hosts, forming well defined races J 
6. Uromyces Scirpi (Cast.) Burr., on Scirpus fluviatilis 
(Torr.) A. Gray, sent by Dr. J. F. Brenckle from Kalmbach Lake, 
Lamoure Co., N. Dak., was sown March 26 on Stum cicutaefolium 
and Hydrocotyle australe, and again May 19 on other plants of 
the same two species, without infection. The species apparently 
is made up of races, a study of which was the aim in this attempt 
at cultures.® 
7. Uromyces Archerianus Arth. & Fromme, on Chloris ele- . 
gans H. B. K., collected Nov. 12, 1914, and again Feb. 7, 1915, 
by Mr. W. A. Archer, at Mesilla Park, N. Mex., was sown April 
15, each collection on a different plant of Cheno podium album, 
with no infection. This new species of rust was discovered in 
abundance upon the campus of the New Mexico Agricultural 
College, with no distinctive aecia in the vicinity. Because of its 
morphological resemblance to Uromyces Peckianus, it was tried 
upon Chenopodium. 
8. Aecidium Iridis Ger., on Iris versicolor L., from the Ren- 
wick Swamp, Ithaca, N. Y., was sent by Mr. J. L. Weimer in 
abundance and in excellent condition, and on July i, the third day 
after collection, was sown on a large and especially thrifty plant 
of the same species of Iris, but gave no infection. A test of the 
spores showed that seventy-five to ninety per cent, were in ger- 
minating condition. Field observations have given little or no 
grounds for considering this rust autoecious, and the present trial 
further emphasizes this view. However, up to the present time 
no one has detected a probable alternate host. 
Successful cultures supplementing previous work. — The 
facts derived by growing the following species of rusts supple- 
ment in a variety of ways the facts obtained from previous cul- 
tures in this series from cultures recorded by other American 
7 For previous attempts at cultures see Mycol. 2: 219. 1910. 
8 For previous culture work see Jour. Myc. 13: 199. 1907; 14: 17. 1908; 
Mycol. 1 : 237. 1909; and 7:83. 1915. 
