108 CYSTOPTERIS DENTATA. 
</CYSTOTTEPJS DENTA'TA. 
THIS is the Toothed Bladder Fern, or Toothed Poly- 
pody, and has heen variously described as Polypodium 
dentatum, Aspidium dentatum, Cyathea dentata, and 
Cystea dentata, while some consider it merely a variety 
of Cystopteris fmgilis. Like C. angustata, we consider 
it sufficiently distinct to be retained as a species. 
Root tufted, small ; rootlets scattered, rather woolly 
and black. Frond, pale green, generally correctly 
doubly-leafleted (bipinnate), some of the lower leaflets 
only, and these in luxuriant specimens, being simply 
leaflted, or cut so as to be nearly leafited (pinnate or 
pinnatifid). The leaflets more or less spread horizon- 
tally ; nearly alternate. Leafits egg-shaped, or rounded 
(our drawing scarcely shows them sufficiently so), 
blunt, abundantly but bluntly toothed ; their ribs wavy, 
their bases not decurrent, though on a winged mid-rib. 
Fructification at the end of the veins, and when nu- 
merous, running together, or confluent, so as to seem 
like a border round the leafit. Stem about one half its 
length without leaflets, very slender, smooth, shining, 
in colour brownish-purple, and rather scaly at the base. 
From six to nine inches high, and not so brittle as in 
C.fragilis. 
This species does not appear to have been noticed by 
the older botanists, and to have been first discovered by 
Mr. Dickson, about the year 1784, in clefts of rocks in 
the highlands of Scotland. In Wales it has been found 
