THE UREDINALES FOUND UPON THE ONAGRACEAE 
545 
number of collections are at hand that the value of the differences, 
indicated by the various descriptions, can be determined. 
Some reasons for the continuation of the specific name Epilobii- 
tetragoni may not be out of place here. While used first as a varietal 
name, and resulting now in a long trinomial, its retention seems ad- 
visable in view of common usage and establishment by leading author- 
ities. Furthermore, the two names following this in priority can 
scarcely be used, the Puccinia combination referring to a short- 
cycled form. Plowright and Grove have used the name Puccinia 
pulverulenta Grev., but this latter name is hardly in use outside of 
Great Britain. 
Pycnia are not frequent in this species, since, as has been often 
pointed out, the aecial mycelium is perennial. Pycnia are found, it 
may be supposed, when infection with basidiospores occurs. Plow- 
right (Monog. Ured. 152. 1889) states that in 1882 he obtained aecia 
from the sowing of aeciospoies upon Epilobium hirsutum. Grove, 
however, doubts the validity of the result. Indeed, it is hardly to be 
expected that a rust should have two repeating spore stages; yet 
probably not beyond the bounds of possibility. Dietel (Flora 81: 
401. 1895) discusses this production of secondary aecia, and states 
that he obtained uredinia from sowing aeciospores. The aecia vary 
somewhat in shape, depending upon conditions, being sometimes short 
cylindric, usually cupulate, sometimes oval. The aeciospores vary 
slightly in size. It has been found rather infrequently that the aecio- 
spores attain a length of 23 fj,, ordinarily being only up to 20 fx in 
length. This is especially true in cases in which uredinia or telia are 
present with the aecia. As far as can be determined from collections 
and studies thus far made, no definite distinction can be found between 
the aecia of Puccinia Epilohii-tetragoni and the aecia of Puccinia 
Veratri, save that the aeciospores of collections placed with the latter 
are ordinarily slightly larger, being more frequently up to 23 /x in 
length. These points are touched upon under Puccinia Veratri in 
this article. 
It is, of course, possible that mixed infections may occur upon 
species of Epilobium. The aecia of Puccinia Veratri and the uredinia 
and telia of Puccinia Epilohii-tetragoni might easily be found occur- 
ring upon the same plant. Field collections of such infections would 
ordinarily be considered as only Puccinia Epilohii-tetragoni. 
The uredinia and urediniospores are rather constant for this 
