394 THE RUSTS OF NOVA SCOTIA. ERASER. 



Life cycle with all the spore-forms Dicaeoma. 



Life cycle with pycnia, aecia and telia. Allodus. 



Life cycle with pycnia, uredinia and telia Bullaria. 



Life cycle with pycnia and telia Dasyspora. 



Puccinia Hieracii (Schum.) Mart. 

 - 0. Pycnia not observed. 



I. Aecia probably not formed. 



II. Uredinia amphigenous, mostly epiphyllous, scattered, 

 punctiform, soon naked, pulverulent. Urediniospores globose, 

 subglobose or ellipsoid, 16-24 by 22-27/x; wall yellowish-brown, 

 echinulate, pores 2. 



III. Telia similar to the uredinia but elliptical to oblong 

 on the stem and darker brown in colour. Teliospores ellipsoid 

 or ovate-ellipsoid, 18-22 by 2 2-3 5 /*, rounded at both ends, not 

 or slightly constricted at the septum; wall brown, equally 

 thickened, finely verrucose; pedicel delicate, hyaline, decidu- 

 ous, mostly short but sometimes exceeding the spore. 



On Hieracium scabrum Michx., Pictou; H. canadense 

 Michx., Macdonald's Barren, C. B. ('Collected by C. R 

 Kobinson). 



Formerly a number of species on Compositae which show 

 little morphological differences were included under P. 



Hieracii. Jacky by cultures showed 

 that infection from teliospores on 

 Hieracium was confined to plants of 

 this genus. This was also shown to 

 hold for some other genera of the 

 Compositae, that is teliospores from 

 of Puccinia one genus of host plants could not 

 infect a different genus. As a result 



cf Jacky's work the rusts on the different genera of the Com- 

 positae are regarded as distinct. 



