254 REPORT OF THE No. 3 



are remarkable for their habit of parasitizing the older needles of balsam. One 

 of them {Peridermium pycnogrande Bell) is found on needles from two to 

 eight years old, and this rust is associated with and is probably the cause of a 

 loose broom-like habit of growth of balsam branches very frequent in Temagami. 

 This rust also appears to pass over to the polypody fern and to be represented 

 there by a rust not before noted. The second new rust (P. pycnoconspicuum 

 Bell) was found on needles three years old. Culture experiments indicate that 

 this is the alternate phase of a rust on the oak fern, Hyalopsora Aspiotus 

 (Peck) Magn., a rust which was believed to pass over to some conifer, but which 

 one, if any, had not heretofore been demonstrated. The peridermia of the 

 first are white and associated with deeply seated spherical pycnia, those of the 

 second are yellow and associated with very large flat and shallow pycnia. 



As a record of distribution a list of the balsam rusts found in Northern 

 Ontario (all in the Temagami Forest Reserve) is appended with the names of the 

 rusts as they are known on the various hosts. 



Abies Balsamea. Alternate Hosts. 



Peridermium columnare (O and I) Calyptospora columnaris (III), 



(Blueberry rust of balsam). on Vaccinium pennsylvanicum and V. canadense. 



Peridermium pustulatum (O and I) Pucciniastrum pustulatum, 



(Fireweed rust of balsam). on Epilobium angustifolium (II and III) and E. 



adenocaulon (II and III). 



Peridermium balsameum (O and I) Uredinopsis Osmundae (II and III), 



(Fern rusts of balsam). on Osmunda claytoniana and O. cinnamomea. 



U. mirabiiis (II and III), 



on Onoclea sensibilis. 

 U. Struthiopteridis (II), 



on Onoclea Struthiopteris. 

 U. Phegopteridis (II and III), 

 on Phegopteris Dryopteris. 

 U. Atkinsonii (II and III), 

 on Asplenium filix-foemina. 

 Peridermium pycnogrande Bell (O and I) . . .U. polypodophila Bell (II), 

 (Fern rust of balsam). on Polypodium vulgare 



(connection with balsam not yet established by 

 artificial infections). 

 Peridermium Pycnoconspicuum Bell (O and I) Hyalopsora Aspidiotis (II), 

 (Fern rust of balsam). on Phegopteris Dryopteris. 



Peridermium elatinum (O and I) Melampsorella elatina (II), 



(Chickweed rust of balsam). on Cerastium vulgatum and Stellaria graminea. 



Caeoma arctica with the alternate phase Melampsora arctica on willows 

 has been found on balsam in Nova Scotia, but has not yet been reported for 

 Ontario. 



The Occurrence and Frequency of Species of Ribes and Grossularia 



IN Ontario. 



Report of Dr. G. H. Duff. 



All present methods for the control of the White Pine Blister Rust, in places 

 where it has already become established, are based upon the eradication of its 

 alternate hosts, the currants and gooseberries. It is of great importance, 

 therefore, to have an accurate knowledge of the different species of Ribes and 

 Grossularia occurring in any region threatened by the disease, together with 

 reliable information concerning their frequency and the correlation (if such 

 exists) between the species and their frequency on the one hand and the forest 

 and topographical conditions on the other. In fact, any information we acquire 



