THE RUSTS OCCURRING ON THE GENUS FRITILLARIA 
Charles C. Rees 
The Fritillaria rusts of Europe and America furnish an interesting 
problem for taxonomic study. In the absence of inflorescence the 
resemblance of the genera Fritillaria and Lilium, upon which occurs 
Uromyces Lilii (Link) Fckl., as interpreted by European authors, is 
striking. This host resemblance, coupled with the fact that the 
rusts infecting them present a somewhat similar gross appearance, 
has resulted in considerable confusion in the naming of many col- 
lections. 
Evidence derived from a study of types and other material of the 
Opsis-Uromyces species on these hosts in the Arthur herbarium has 
led to the conclusion that the species on Fritillaria in Europe is mor- 
phologically quite separate and distinct from the rust with the same 
life-cycle on Lilium in that region and from the American form on the 
same host as well. The writer is therefore inclined to recognize as a 
valid species, Uromyces Fritillariae (Schlechtd.) Thiim., to which all 
of the European specimens on Fritillaria, seen by the writer, should 
be referred. All of the Uromyces collections on Lilium in Europe 
belong, according to the writer's interpretation, to the species formerly 
known as Uromyces Lilii (Link) Fckl. This species was first described 
by Strauss^ under the name Uredo aecidiiformis on Lilium candidum. 
Although he used the generic term, Uredo, in designating the form, it is 
evident from the text that telia are described. For these reasons the 
species should take the name Uromyces aecidiiformis (Strauss). Re- 
gardless of the fact that the type of Uromyces Miurae ^ Sydow has 
not been examined, it is the writer's opinion that the American rust 
on Fritillaria is identical with it. Such disposition of a rust new to 
this country is not unusual when it is remembered that certain species 
of rust and other fungi have for a long time been known to be 
indigenous to Japan and eastern Asia as well as to the western and 
particularly to the northwestern coast of North America. 
1 Ann. Wett. Ges. 2: 94. 1811. 
2 Ann. Myc. 11: 94. 1913. 
368 
