Cistopteris Fragilis, Bernhardt . 
BRITTLE BLADDER FERN. 
Root — Black and wiry, candex small and somewhat flat. 
Frond — Lanceolate, bipinnate, from four to sixteen inches 
long. 
Stipes — One-third the length of the Rond, varying with 
the situation of the plant. 
Pinnae — Lanceolate, alternate, pinnate; the lower pair 
deflexed, and shorter than the upper pinnse. 
Pinnules — Oblong or linear-lanceolate, deeply pinnatifid, 
serrated. 
Venation — Mid vein sinuous, lateral veins branched. 
Fructification — Clusters of capsules near the extremity 
of each vein, upon a membranous envelope. 
Habitat — Clefts of stone, in walls and mines; on high 
and exposed situations, dwarf in all respects. A variable 
species, attaining the greatest perfection in wide fissures 
of rocks. 
Locality — Plentiful about Matlock, Buxton, and in all 
the limestone districts: occasionally on sandstone. 
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