BRITTLE BLADDER-FERN. 57 



The rootstocks are of the creeping order, but while in some 

 species the fronds arise at a distance apart, in others they are 

 all produced close to the growing point, which gives them a 

 tufted appearance. The fronds have pinnate or forked veins, 

 and the degree of dissection varies from simply pinnate to four 

 times pinnate. They are all deciduous, that is, their fronds die 

 on the first approach of winter. They are rock-plants that 

 prefer cool moist situations. 



Bladder-fern is merely a book-name, being a translation of 

 the Greek Cystopteris. 



Brittle Bladder-fern (Cystopteris fragilis). 



The distinctive epithet "brittle" does not apply specially 

 to this species as contrasted with its congeners ; but in the 

 absence of folk-names, authors, upon whom is laid the necessity 

 of providing some English title, are glad often to fall back 

 upon a translation of the Greek or Latin words chosen as the 

 scientific label for the species, as has been done in this case. 



The Brittle Bladder-fern has a prostrate rootstock thickly 

 covered by pale-brown lance-shaped scales ; at the growing 

 point these scales being new are orange-coloured. The new 

 fronds arise from near the growing point, and so give the plant a 

 tufted appearance, though no proper " crown " is formed as in the 

 case of the Male Fern, etc. The frond is lance-shaped, and 

 from six inches to a foot in length, of which about a third 

 consists of the brittle brown stipes, clothed at the base only 

 sparingly with golden scales. There is a slight expansion of 

 the midrib in the upper part ; and the greatest breadth of the 

 frond is about its middle. (Plates 51, 61.) 



The frond is usually twice pinnate. The pinnae are triangular, 

 pinnate, and the pinnules are pinnately cut into lobes which are 

 very close together. The sori are produced in varying numbers 

 on each segment ; there may be two or a dozen, or any number 



