64 HOW TO KNOW THE FERNS 



appearance of the Brittle Bladder Fern is of a 

 delicate nature and it has a very distinctive 

 appearance. 



Properly speaking, the Brittle Bladder Fern 

 is a mountain species, though it sometimes occurs 

 on old walls or in rocky clefts which are not very 

 elevated. The species is widely distributed in 

 all parts of Great Britain, though in frequented 

 districts it is soon exterminated. The Brittle 



Cystopteris fragilis. The Brittle Bladder Fern. 



Bladder Fern does not seem to grow very well 

 in the open rockery, though it is fairly easy to 

 cultivate in pots. The fronds die down at the 

 approach of winter. There are a certain 

 number of varieties. 



Cystopteris montana. Here the specific name 

 is formed from the Latin word mons, " a 

 mountain." The Mountain Bladder Fern. 



This is the only other recognized species of 

 Bladder Fern to be found in the United King- 



