A Dictionary of Choice Ferns. 
195 
CYSTOPTKRIS— continued. 
and covered with the persistent and somewhat fleshy bases 
of the old stalks. In mature plants they are usually 6in. 
to 12in. long and Sin. to 4in. broad at their widest part. 
They are usually spear-shaped, frequently much elongated 
upwards, and twice or thrice divided half-way to the mid- 
rib ; their broadest part is the base, where the leaflets 
are often 2in. to Sin. long, lin. broad, and divided into 
narrow-oblong segments cut down nearly to the midrib and 
slightly toothed ; thence they gradually narrow to their 
extremity, having, according to Eaton, a narrower and 
more tapering outline than any other known North 
American Fern with compound and feathery fronds. The 
stalks are usually 4in. to Gin. long, very slender, smooth, 
and of a brittle nature, usually green, except at the base, 
where they are -dark brown ; but sometimes the whole stialk 
and rachis are brownish. The sori are produced so 
abundantly as to be found on all portions of the frond, 
even to the base ; they are disposed two to twelve to a leafit 
and usually in two rows, one in each segment. 
C. fragilis. 
This is probably the commonest of the known species of 
Cystopteris, and it possesses a peculiarly cosmopolitan char- 
acter, being found nearly the world over. It is the Brittle 
Fern of North America, and the Brittle Bladder Fern of 
Britain, having been known here for over two centuries. 
It is readily distinguished by its fronds, 4in. to Sin. long, 
l^in. to Sin. broad, somewhat spear-shaped, and twice or 
thrice divided half-way to the midrib, being abundantly 
produced from a close, tufted crown, and borne on smooth, 
reddish-brown stalks 2in. to 4in. long, of a very slender 
and brittle nature. The largest leaflets, lin. to l^in. long 
and fin. broad, are divided into oblong leafits, which are 
cut down into bluntly- or sharply-toothed lobes. The 
texture is soft and papery, and the abundant sori are dis- 
posed two to twelve to a pinnule. This species requires a 
suitable situation to develop and preserve its true character, 
as it is very liable to alter its growth according to its 
position. Of its numerous varieties the best, from a 
gardening point of view is : 
C. f. Dickieana. 
Undoubtedly this remarkably pretty, dwarf Fern is 
the most distinct variety, and it possesses the property of 
reproducing itself so truly from spores, that some authori- 
ties are inclined to accord it specific rank. It differs 
from the type in its much denser habit and more ovate 
fronds, the height of which is seldom above 5in,, 
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