5 48 Filices Cystopteris. 



7. CYSTOPTERIS. 



Ehizome tufted or creeping. Fronds tufted or scattered, 

 1- to 4-pinnate, delicate in texture ; veins pinnate or forked, 

 ultimate venules free. Sori dorsal, globose on the free venules. 

 Indusium membranous, convex, attached to the venule below 

 the sorus. There are five species from temperate regions. 

 The name is from /evcrm, a bladder, and TTTSpls, a fern, referring 

 to the form of the indusium or involucre. 



1. C.frdgilis. Common Bladder Fern. A handsome tufted 

 Fern from 6 to 12 inches high, with bright green pinnate or 

 bipinnate fronds on short brittle stipes. Pinnules triangular 

 or ovate ; -rachis slightly winged. Sori few or many on each 

 pinnule. Throughout Britain, though rare in the south, and 

 widely spread in both the north and south temperate regions. 

 C. dentata and C. Dickieana are varieties of this species. 



C. montana is a delicate mountain species with 3- or 4- 

 pinnate fronds, found at a great elevation in Scotland. 



Onoclea sensibilis is a hardy North American Fern with 

 separate barren and fertile fronds. The former are about 18 

 inches high, simply pinnate, with long lanceolate toothed pinnae, 

 and the shorter fertile ones are bipinnate. Indusium inferior, 

 bursting irregularly. 



Struthiopteris Germdnica is an allied Fern having the fronds 

 disposed in a tufted rosette. The barren fronds are from 2 to 

 3 feet high, lanceolate, bipinnate with narrow pinnules. The 

 fertile fronds are pinnate, and appear within the barren ones, 

 and are much shorter. A widely diffused plant. Both this and 

 the last are very handsome and desirable for planting in damp 

 places, on the margins of pools, or partially in water. 



8. W60DSIA. 



Tufted dwarf Ferns with pinnate fronds, of which the stipes 

 are usually jointed above the base. Sori globose ; indusium 

 attached under the sorus, at first cup- shaped and entire, ulti- 

 mately breaking up into filiform segments. There are 14 

 species described, from arctic and alpine regions. This genus 

 is dedicated to Joseph Woods, an English botanist, author of 

 the ' Tourist's Flora,' &c. 



W. hyperborea and W. ilvensis are found in Britain at con- 

 siderable elevations in Wales, North England and Scotland. 

 In the first the ultimate lobes of the linear-lanceolate fronds 

 are entire, and in the second they are crenate, and the frond 

 is broadly lanceolate in outline. 



