XXXVII. VIOLET RUSTS OF NORTH AMERICA. 
J. C. ARTHUR anp E. W. D. Hotway. 
A rust of violets, in its three forms of ecidium, uredo and 
teleutospore, is common throughout North America upon nearly 
all indigenous species of the genus Vzola. For the most part 
it belongs to a single species, Puccenta Viole (Scuum.) DC., 
which is also the common violet rust of Europe and of some 
other regions. This, at least, is the conclusion to which we 
have arrived after a rather extended study of considerable ma- 
terial. Beside the one common rust there isa peculiar “czdium 
throughout the eastern part of North America, and one species 
of Puccinia in the western part, both distinctly American. 
In this connection we desire to acknowledge the kindness of 
the New York Botanical Garden, the Botanical Department of 
the University of Illinois, and of the Iowa State College, in 
loaning material from their herbaria, and to extend our thanks 
to their representatives. We wish alsoto thank Dr. J. J. Davis, 
of Racine, Wis., and Mr. E. Bartholomew, of Rockport, Kans., 
for aiding us with specimens and information. Weare further- 
more grateful to Mr. Stewardson Brown, curator of the herba- 
rium of the Philadelphia Academy of Sciences, for the privilege 
of examining material in the Schweinitz collection, and to the 
custodians of the Gray Herbarium of Harvard University and 
of the New England Botanical Club, from the examination of 
whose phanerogamic collections of V7o/a, five specimens of rust 
were obtained in the former instance and three in the latter. 
In this article for conciseness we have used in addition to 
the usual I, II and III for designating the ecidium, uredo and 
teleutospore stages, the sign O for the spermogonial stage. In 
citing specimens these signs are put into large type when the 
stage is present in abundance, and into small type when sub- 
ordinate and in small amount. 
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