CRYPTOGAMIA— FILICES. Cystea. 297 



About the margins of clear springs, in the south of England. 



In several places near Tonbridge. Mr. T. F. Forster. 



Perennial. June, July. 



Scarcely one-fourth so large as the preceding, of which nevertheless 

 some good botanists have thought it a variety ; and indeed after 

 long cultivation, though raised originally from seed, it consi- 

 derably approaches that species. In a wild state the fronds are 

 of a more narrow lanceolate figure, and of a paler pellucid 

 green ; the main stalk occasionally scaly, but in general quite 

 smooth, and exactly quadrangular, though the latter circum- 

 stance varies. Leaflets shorter, and somewhat less linear, than 

 in Filix faniina, deeply serrated, or partly pinnatifid, their seg- 

 ments sharply cut, without bristly points. Masses by the side 

 of the midrib of a few of the lowermost lobes of each leaflet, 

 solitary, oblong, though short, and ultimately roundish, or oval. 

 Coter at first oblong, soon becoming kidney-shaped, or almost 

 orbicular, with a lateral notch, flat, thin, membranous and jag- 

 ged. Capsules dark brown. 



465. CYSTEA. Bladder-fern. 



Cystopteris. Bernhardi in Schrad. New Journ. r. 1 . p. 2. 26. 1. 1 ./. 9. 

 Cyathea. Fl. Br. 1138 j but not Jet. Taurin. v. 5. 416. n. 1—4, 



nor Tracts 25 1 . n. ) —4. See Plum. Fil. t. 2. 

 Athyrium. Spreng. Crypt. f. 30. 



Nat. Ord. see «. 4-63. 



Masses of capsules orbicular, convex, scattered variously 

 over the back of the frond, between the midrib of each 

 leaflet, or lobe, and the margin. Capsules several, glo- 

 bose, on short stalks ; each of 1 cell, and 2 equal, hemi- 

 spherical valves, bound together by a transverse jointed 

 ring, which finally separates them, when dry, by its 

 elasticity. Seeds numerous, roundish, very minute. Cover 

 membranous, white, orbicular, concave, fixed by a nar- 

 row point of attachment at the side of each viass under- 

 neath ; at first enfolding the whole ; but subsequently 

 separating, turned to one side, unequally jagged, flaccid 

 and irregular, sometimes pointed ; finally obliterated, or 

 concealed by the swelling capsules. 



Fronds oblong, of humble growth, erect, very delicate in 

 habit, compound, finely cut. Stalk about half the length 

 of the leafy portion, smooth. Leafets ovate or oblong, 

 serrated, toothed, or wavy. Masses small, with a deli- 

 cate, white, globular cover while young, which renders 

 them very conspicuoii;? in an early state, but afterwards 



