THE RUSTS OF NOVA SCOTIA. FRASER. 403 



This species is very common on its host in the districts 

 near Pictou. 



Sydow states that the aecial stage is raraly collected, the 

 only collections being in Finland, Siberia and once in Germany 

 As this stage is conspicuous and not likely to be overlooked, he 

 regards the aecia as not necessary for the fungus and only 

 developed under favourable conditions. 



A collections of the aecia was made near Pictou on July 3, 

 1909, in a shaded position. There was such a rich development 

 that in some cases the host plants were killed. 



Puccinia Thalictri Chev. 

 Polythelis Thalictri (Chev.) Arthur. 



0. Pycnia hypophyllous, few, scattered among the telia. 

 I & II. Aecia and uredinia not formed. 

 III. Telia hypophyllous, scattered, never confluent, cir- 

 cular, 2-5 mm. across, soon naked, pulverulent, dark chestnut- 

 brown, surrounded by the ruptured epidermis. Teliospores 

 ellipsoid or oblong ovate, sometimes very irregular, much con- 

 stricted at the septum, the cells separating easily, 15-30 by 

 22-52/x; walls dark brown, uniformly thickened, very coarsely 

 and evenly verrucose ; pedicel delicate, hyaline, about the length 

 of the spore, deciduous. 



On Thalictrum polygonum Var. hebecarpum Fernald, 

 Truro, September 3, 1908 ; September 1, 1909 ; August 9, 1910. 

 Arthur places this species in the genus Polythelis on the 

 basis of the teliospores forming 

 heads by being attached by short 

 pedicels to a common stalk, which 

 is short and inconspicuous. 



It seems to be rare, as it was 

 found on only & few plants on the 

 banks of the Salmon River near 



Teliospores of Puccinia Thalictri. 



Truro, although search was made 



for it in other places. The fungus appears on the same plants 

 each vear and is for that reason regarded as perennial. 



