THE RUSTS OF NOVA SCOTIA. FKASEB. 



Arthur (Jour. Myc. 12:23. 1906) by cultures showed the 

 connection of the aecia on Eupatorium and has confirmed this 

 result by recent cultures. (Jour. Myc. 13:193. 1907; 

 Mycologia 1:233. 1909). 



Form Genera. 



These are imperfect forms, which occur in only one stage 

 and cannot be assigned to their proper genera till the complete 

 life cycle is known. It is convenient to assign them to form 

 genera till their true position is determined. The forms included 

 here are Uredo, Caeoma, Aecidium, Peridermium and 

 Roestelia. 



Uredo. 



Uredo forms are uredinia that have not been connected with . 

 their telial form. They have the characteristics of the uredinial 

 stages of the Pucciniaceae. It is possible that some possess 

 perennial mycelium so that they can dispense with teliospores, 

 or that the urediniospores may carry the fungus over the 

 winter. I have not collected any of them in Nova Scotia. 



Aecidiunr 



Peridium present, usually cup-shaped, spores in chains. 

 Forms placed here are simply the aecial stages of unconnected 

 rusts. The form genus Peridermium is sometimes included. 



Aecidium Compositarum Var. Solidaginis. 



0. Pycnia amphigenous, in small groups on the spots that 

 bear the aecia, inconspicuous. 



1. Aecia chiefly hypophyllous, on yellow spots or areas, 

 cylindrical or cup-shaped, low, margin lacerate. Aeciospores 

 angular-globose or ellipsoid, about 15-19/*; wall colourless, 

 finely verrucose; contents yellowish, becoming colourless. 



On Solidago canadensis L., 8. rugosa Mill., Pictou. 



