MOUNTAIN BLADDER FERN. 53 



marginal teeth. It is of a deep-green colour and 

 very transparent. It has only been found by Dr. 

 Dickie in sea-caves near Aberdeen. 



Few ferns can be cultivated with greater facility 

 than these. They may be grown in the open garden- 

 border, or in closed cases ; they do best, however, in 

 the open air, as they are subject to the attacks of 

 a red mildew, which is increased by confinement. 



MOUNTAIN BLADDER FERN. 



C7STOPTERIS MONTANA. 



[Link, Hooker and Arnott, Babington, Moore, 

 and Bentham.~\ 



SYNONYMS. 



CYSTOPTERIS MYRRHIDIFOLIUM. Villars ana 



Newman. 



POLYPODIUM MONTANUM. Allioni. 

 ASPIDIUM MONTANUM. Swartz. 



IT grows from four to eight inches high. The root 

 is creeping. The fronds grow simply, and are tri- 

 angular bipinnate ; the pinnae of the lowest pair 

 being much larger and more divided than the others. 

 The whole plant greatly resembles the Oak Polypody, 

 only it is of a much more delicate texture. The sori 



