154 
BRITISH FERNS. 
On the Continent, it is frequently found in the 
Southern Alps and Pyrenees, and the mountains of 
Greece, but nowhere at a less elevation than six thou- 
sand feet. Mr. Newman calls this fern Cystea regia , 
and accounts it a variety of fragilis . 
24. Cystopteris montana, Bernh. Mountain 
Bladder-fern. 
Caudex long, very slender, creeping, scaly. Stems distant, 
slender, scaly. Fronds 4 to 5 inches long, triangular. Pinnse 
spreading, the lowest ones large. Leaflets ovate, pointed. In- 
volucres thin, hood-shaped, serrated at the edge. 
This very rare fern is as elegant as it is valuable. 
The caudex creeps as widely as that of the Oak-fern, 
like it, throwing out fibrous 
branching roots, and putting 
up single fronds here and 
there. The frond is trian- 
gular in form, the lowest pair 
of pinnae so nearly opposite 
one another and so fully de- 
veloped as to give the frond 
a three-branched appearance, 
like that of the Polypody, to 
which it has been already 
compared. The stems of the 
pinnae are slightly winged. 
The leaflets are of a delicate pale green, the veins 
branched, the sori situated on the side branches of the 
veins and covered by the hooded involucre. 
The Mountain Bladder-fern is found among many of 
our mountain ridges, as the Breadalbane, Aberdeenshire, 
and Perthshire hills, and on Ben Lawers. 
