THE RUSTS OF NOVA SCOTIA. FRASER. 879 



12-17 by 20-30M, rounded, obtuse or acute at apex, mostly 

 narrowed below; wall light chestnut-brown, thickened at apex, 

 5-10/A, smooth; pedicel yellowish, persistent, about the length 

 of the spore. 



On Juncus filiformis L., Pictou. 



Nothing is known of the aecial stage of this rust. It was 

 found in only one place, and, though careful watch was kept 

 for two seasons in the neighbourhood, no aecia appeared except 

 those that have already been connected. 



This collection adds a new host, as all previous collections 

 were on Juncus effusus L. 



This species is found throughout the eastern United States 

 on Juncus effusus L. It has passed under the name U. Junci 

 (Desm.) Tul., but Arthur (Jour. Myc. 13: 192. 1907) shows 

 that it is morphologically distinct, especially as the uredinio- 

 spores are echinulate and four-pored instead of verrucose and 

 two-pored, as in U. Junci. He gives the following key to 

 separate the three common species of Uromyces on Juncus: 



Urediniospores verrucose, pores 2, equatorial U. Junci. 

 (Desm.) Tul. 



Urediniospores echinulate, pores 4, equatorial U. effusus 

 Arth. 



Urediniospores echinulate, pores 5-6, scattered U. Silphii 

 (Syd.) Arth. 



Uromyces Polygon! (Pers.) Fuck. 

 Nigredo Polygoni (Pers.) Arth. 



0. Pycnia yellow to honey-colour, in small groups. 



1. Aecia mostly hypophyllous, crowded in roundish 

 groups, peridium rather low, with broad, whitish, torn edges. 

 Aeciospores subglobose, 16-18/*, pale yellow to orange, 

 verrucose. 



