28 
FERNS. 
[ Cistoptcris . 
CISTOPTERIS, Bern. BLADDER-FERN. 
(xiolof, a bladder, vjhft;, a fern ; the indusiums being like bladders.) 
A, one of the pinnee of the frond of Cistopteris frayilis. B, a lobe magnified. 
C, young sori and indusia. D, soms ait transversely. E, theca. F, seed. G, 
indusium magnified from Bauer’s “ Genera Filicum.” H, ditto from Schott’s 
“ Genera Filicum.” 
The genus is distinguished by its indusiums being inflated like bags, not being 
attached by a central column , but only by the edge nearest this rachis, and 
finally, either quite bent back or thrown off altogether. They first open on the 
top, or on the side nearest the apex of the frond or pinna. 
1 .—CISTOPTERIS DENTATA. 
TOOTHED BLADDER FERN. 
(Plate 2, fig. 1 .) 
Cha. Frond bipinnate, oblong, lanceolate. Pinnae ovate, 
lanceolate. Pinnules ovate, obtuse, crenate. Sori distinct. 
Syn. — Cystea dentata, Eng. Flo. — Cyathea dentata, Eng. Bot., Dav. W. Bot. 
Galp. — Polypodium dentatum, Dicks., With., Hull. — Aspidium dent., 
Swz., Willd., Hook, in FI. Sco., Decan. — Athyrium dentatum, Gray. 
Fig. — E.B.. 1588. — Pluk. Phyt. 179, f. 5 (a cultivated specimen). — Bolt 27. 
Des. — Root tufted, black, fibrous. Fronds numerous, oblong, 
lanceolate, 6 to 9 inches high, herbaceous. Stem slender, smooth, 
green except at the lower part, winged near the apex, without 
pinnae for one-third of its height, above this bearing about fourteen 
pairs, opposite to each other. Pinnae ovate, blunt, length twice 
their width, their main rib winged. Pinnules about ten pairs in the 
larger pinnae, decurrent, ovate, obtuse, crenate or toothed, very 
rarely cut into distinct lobes, unless in luxuriant specimens, when 
the frond becomes wider, the pinnules very deeply cut, and some- 
times petioled, hut never losing their ovate, roundish, blunt form. 
Sori scattered, and always remaining distinct ; Sir J. E. Smith says 
confluent, but this does not agree with any of my specimens, though 
probably in hot weather they may be found so. 
Our plant Cistopteris dentata is to be known from every state of Cistoptcris 
fragilis, in the shape of its frond and pinnules, which in this are very much 
blunter, rounder, and less divided ; its ruchis also is shorter and less brittle, and 
the whole smaller than the next species. 
