PLANT DISEASES OF CONNECTICUT. 353 
ferent and had never been collected before in the state. This 
rust we determined to be Peridermium delicatulum, and Kern, 
to whom we sent specimens, verified our determination, and 
kindly sent specimens of the type for comparison. This 
rust was originally described in 1906 by Arthur and Kern (Bull. 
Torr. Bot. Club 33: 412) from Florida on leaves of Pinus sp., and 
apparently had not been collected since. 
The illustration shows very well some of the macroscopic 
differences between this species and our more common Perider- 
mium acicolum. These differences are as follows: (1) The 
peridia of P. delicatulum are very inconspicuous, being deeply 
embedded in, and standing very slightly above, the leaf tissues, 
and open by a long slit; while those of P. acicolum stand up 
prominently, 1-3 mm. above the surface of the leaf, and fre- 
quently remain as white, tongue-shaped elevations after the spores 
are shed. (2) The fresh spore-masses of the first species are less 
dusty, and are crimson, as compared with the orange-colored 
sori of the other species. (3) Microscopically the spores are 
smaller (18-29p x 17-21», subspherical or cuboidal to ovoid), and 
with minute verruculations, while the spores of P. acicolum are 
covered with coarse, scale-like tubercles. 
From observations made at the time, though not proved by 
inoculation experiments, it seems very probable that P. delicatu- 
lum has, like P. acicolum, its III stage as a Coleosporium on 
Solidago. Immediately under and close to the branch of Pinus 
rigida bearing the P. delicatulum was found a specimen of 
Solidago graminifolia var. Nuttallii containing the II stage of an 
undetermined Coleosporium. The spores of this were very 
similar in color and in fine verruculations to those of Perider- 
mium delicatulum on the pine, just as are those of the II stage of 
Coleosporium Solidaginis on Solidago rugosa similar in color 
and coarse tubercles to those of its peridial stage, P. acicolum. 
We have reported before that the spores of all the specimens on 
Solidago, etc., of the II stage of so-called Coleosporium Solidag- 
inis were not alike, and an examination of specimens on Solidago 
graminifolia var. Nuttallii already in the herbarium showed that 
these had the fine verruculations of this new species. It is hoped 
that we shall- be able later by inoculation experiments to fully 
determine this species on the goldenrod and connect it with the 
suspected stage on pine. 
o 
