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: (i) 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 (i 8-29/4 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. 



