530 
G. R. BISBY 
cycled autoecious species discussed. The idea embodied is somewhat 
different from that of physiological or biological races. The latter 
designation of races is used, in the Uredinales, in cases where cultures 
have shown that there are certain restrictions upon the transference 
of a rust from host to host. The idea made use of here is that of mor- 
phological races — races separated upon the same ideas of differenti- 
ation upon which species are ordinarily based, but the differences being 
not of sufficient value nor constancy to make possible a separation 
into species. In the absence of cultural data, these races are suggested 
if or convenience. The idea is somewhat that of varieties under a 
•species. The word variety is not used, however, as that would result 
in a cumbersome, and perhaps inaccurate, nomenclature; a tentative 
division into morphological races seems to afford an opportunity to 
systematize the arrangement of specimens representing rather variable 
species. 
A perfectly consistent treatment of the evening primrose rusts, 
embracing all the species, is now impossible. This study is therefore 
made primarily in an attempt to draw attention to some of the ques- 
tions demanding answer, and in the hope that collections, cultures, 
and studies may eventually be made to clarify and arrange our knowl- 
edge of this interesting group of rusts. 
The main points brought out in this paper are: the grouping to- 
gether of the long-cycled autoecious forms of Puccinia upon the 
Onagraceae into one species, and the considerations involved; some 
notes upon the heteroecious forms which include the Onagraceae in 
their life cycle; some correlations indicated between different species 
and races; keys to aid in the diagnosis of the various rusts in question. 
Several incidental points are discussed. Species not known in North 
America are dealt with only briefly. Descriptions of several of the 
species under discussion are not added here, since that would appear 
to be an unnecessary duplication. References to descriptions easily 
available are given in such cases. 
The keys herewith presented offer difficulties at some points, due 
partly, as pointed out above, to the fact that correlated species possess 
spore-forms morphologically indistinguishable. The different con- 
siderations, however, usually can be utilized to place a specimen. 
The abbreviations N.A. (North America), S.A. (South America), 
Eur. (Europe), etc., and the symbols O (pycnia), I (aecia), II (ure- 
dinia), and III (telia), used in places, are for brevity. 
