THE UREDINALES FOUND UPON THE ONAGRACEAE 543 
show similar variability; in fact, a gradual gradation is to be noted. 
Here then, the two extremes in these forms of Onagraceous rusts 
occur upon the same genus of host, to a great extent upon the same 
species, and shade by degrees the one into the other. 
The genus Chylisma shows much variation in the rust upon different 
species; for example, a collection upon Chylisma hirta A. Nels. possesses 
teliospores 21-24 by 37-50 At, the wall chestnut-brown, smooth, the 
apex 7-1 1 fjL, the pedicel once or twice the length of the spore; another 
collection upon Chylisma scapoidea scorsa A. Nels. shows teliospores 
but 16-20 by 26-34 M> the wall from cinnamon- to chestnut-brown, 
appearing almost as if verrucose, the apex but 4-7 thick, the pedicel 
short. 
The evidence obtained from the large number of collections points 
unquestionably toward great variability in morphological characters 
within the forms upon these Onagraceous hosts. In a general way 
differences are found between the rusts upon these different hosts 
which ordinarily may be utilized to indicate the placing of the rust 
within morphological races, as is indicated later in this article; yet 
specific distinctions, it seems to the writer, can not be drawn. It is 
significant that, in the work upon the correlated long-cycled autoecious 
Uromyces forms upon the Onagraceae, of which four species had been 
described, it was considered desirable also to combine them, as already 
published in the North American Flora. 
The long synonymy involves some names about which confusion 
exists in the literature. The name Aecidium pulchellum Schrad. is 
omitted from the synonymy, being listed by DeCandolle as a synonym 
of his Aecidium Epilobii in Fl. Fr. 2: 238. 1805. As no reference to 
any publication is given, it may be assumed that Aecidium pulchellum 
was a manuscript or herbarium name, never established. Puccinia 
tenuistipes Opiz is included on the authority of Sydow, who states 
that it occurs on Epilobium hirtum and is fully identical with Puccinia 
Epilohii-tetragoni. As listed by Opiz, Seznam Rost. Kvet. Ceske 
139. 1852, one can hardly determine what is referred to. Aecidium 
pallidum Schneid. is also included on authority of Sydow (/. c.) also 
Schroeter (/. c, p. 319), it having been found that Schneider errone- 
ously determined his. host plant, considering it to be Ly thrum Sali- 
caria, whereas Schroeter finds the host in reality to be Epilobium 
hirsutum. 
Puccinia Epilobii DC. Fl. Fr. 6: 6i. 1815, is used by Saccardo, 
