274 BOTANICAL GAZETTE [APRIL 
PucciniA VILFH A. & ZH. 
This species of rust, better known as P. Sydowiana Diet., is 
necessarily restricted in the vicinity of Lafayette to the few 
localities where the host, Sporobolus longifolius,3 is to be found. 
My attention was called to the fact by Miss Lillian Snyder that in 
such localities the exceedingly common upright verbenas were 
richly covered with 4icidium verbenicola K. & S., and with no 
other species of ecidia in the vicinity. Going over the ground 
myself, I found that the verbena plants, Verbena stricta being 
particularly abundant, were more thickly studded with eeidia 
the closer they stood to tufts of rusted Sporobolus, and that 
fifty feet away from such source of infection they would be 
entirely free. ' 
Cultures were undertaken in 1898, but too late in the season 
to secure results. In the mean time a morphological resem- 
blance was observed between the spores of &cidium verbenicola 
and the uredospores of Puccinia Vilfe, that gave another hint 
at genetic relationship. Both sorts of spores were approxi- 
mately obovate, with colorless walls, greatly thickened at the 
apex, and papillose instead of echinulate. Successful cultures 
have shown that these rather uncommon characters meant more 
_ than a coincidence in thiscase. It is the first time, so far as the 
writer knows, that any significant resemblance has been pointed 
out between the spores of ecidia and uredo of the same species. 
For some unexplained reason I was unsuccessful in germi- 
nating the teleutospores of P. Vilfe, although they were taken 
a number of times directly from the field. But with zecidio- 
spores the results were ample and convincing. The dates are 45 
follows: 
I 
4 
May 31, AEcidiospores from Verbena stricta on Sporobolus longifolius ; a 
fo, uredo. 
June 9, Aicidiospores from Verbena stricta on Sporobolus longifolius ; it 
21, uredo. 
3Since this paper was read I have discovered that the grass under observation 
was Sporobolus longifolius (Torr.) Wood, instead of S. asper, as given in the manuscript 
and printed in Science 10: 565, and Proc. A. A. A. S. 48: 299. The latter grass does 
not grow in this region. 
