358 



THE RUSTS OF NOVA SCOTIA — FHASER. 



ncuminate above, with a' straight or l^ent beak, usually 8-1 5/i, 

 sometimes obsolete, narrowed below and truncate; wall colour- 

 less, thin, smooth except for two lonuitudinal lines of delicate 

 cilia. 



III. Teliospores crowded in and lieneath opidonnal cells, 

 globoid, ellipsoid or somewhat irreo-idar, about 20-27/^ broad 

 bv 18-32/i high, usually four-celled, sometimes two to many- 

 celled; wall colourless, thin, smooth. 



On Osmunda cinnamomea L., 0. Claytomana L., Pictou, 

 Truro, Folleigh Lake, Oakfield; 0. regnUs L., Oakfield. 



This species is very 



® 



common and widely dis- 

 tributed on Osmunda 

 cinnamomea and 0. Clay- 

 toniana. It is usually 

 conspicuous from the 

 sharply defined yellow 

 areas between the veins. 

 Collections in August and 



September show abundant development of both the uredinia 

 and telia. 



Uredinopsis mirabilis (Peck) Magn. 



I. Aecia hypophyllous, scattered or somewhat gregarious, 

 roundish, small; peridium strongly developed. Aeciospores 

 angularly obovate or polyhedral, 15-20 by 24-36^; wall colour- 

 less, medium thick, minutely verrucose. 



IT. Uredinia hypophyllous, scattered on discoloured 

 areas, usually bounded by the veins, roundish, small, soon 

 dehiscent by an apical rupture; peridium delicate, Uredinio- 

 spores fusiform, ovate-fusiform or clavate, 12-17 by 27-5. 5/^, 

 acuminate above tapering into a beak 3-14/* long, wall colour- 

 less, thin, smooth except two lines of closely set minute spines. 



III. Teliospores thickly scattered in the mesophyll of the 

 leaf, globose or often broader than wide, usually about 22-32/* 



Uredinopsis Osmundce. Two aeciospores. Two 

 urediriospores. Teliospores, surface view, 

 cro-^s section. 



