1058 



THE FERN FAMILY. 



Fie. 1289. 



extremities of most of the lobes of the 

 segments. 



In the fissures of moist rocks, at the 

 entrance of caves and wells, and other 

 situations sheltered from cold, as well as 

 from sun and drought, in most of the 

 tropical and warmer parts of the globe ; 

 common in southern Europe, extending 

 northward over the greater part of 

 France, but scarcely into Germany. In 

 Britain, only in the south-western coun- 

 ties of England, in South Wales and 

 Ireland. Fr. all summer. 



XIY. BLADDERFERN. CYSTOPTERIS. 



Delicate Ferns, with twice or thrice pinnate fronds. Sori small, 

 circular on the under surface, enclosed, when young, in a very thin, 

 globular or hood-shaped membrane, which opens out irregularly into a 

 cup under one side, and often disappears early. 



A small genus limited to the colder or mountainous regions of both 

 hemispheres. 



Fronds oblong-lanceolate, the lowest pinnas decreasing in size 1 . Brittle B. 

 Fronds broadly triangular or rhomboidal, the lowest parir of 



pinnas the largest 2. Mountain B. 



1. Brittle Bladderfern. Cystopteris fragilis, Bernh. 

 (Fig. 1290.) 



{Cyathea fragilis and dentata, Eng. Bot. t* 1587 and 1588.) 



Bootstock shortly creeping. Fronds tufted, usually under a foot 

 long, oblong-lanceolate in their general outline, twice pinnate ; the 

 longest primary pinnas towards the middle of the frond, 1 to 1\ 

 inches long, decreasing towards both ends. Stalks slender, without 

 scales. Segments lanceolate, deeply pinnatifid, or the lower ones 

 pinnate, with small, oblong, more or less crenate lobes, all obtuse, not 



