CYSTOPTEBIS DAVALLIA. 



137 



CYSTOPTERIS. 



A genus separated from Aspidium by Bernhardi. Name 

 derived from Jcystos, a bladder, and pteris, a Fern. Distin- 

 guished by spore-masses being 

 roundisli in the middle of the 

 back of a vein or veinlet, 

 covered by a thin membranous 

 indusium, inserted by its broad 

 base at the under side of the 

 spore-mass and covering it; 

 opening by a free, usually 

 long extremity, pointing to- 

 wards the apex of the seg- 

 ment, ultimately reflexed. 



CYSTOPTEEIS TENUIS 

 (Slender), Fig. 63. Native of 

 North America. Fronds 12 

 to 15 inches long, oblong- 

 lanceolate, nearly three-times- 

 divided, light green ; pinnules 

 Fig. 63. Cystoptens tenuis. (Pinna na- 

 tural size and pinnule magnified.) ovate-oblong, deeply cut into 



segments, which are bluntly toothed. 



DAVALLIA. 



Commemorative of Edmund Davall, a Swiss botanist. 

 Spore-masses contained in a cup-like cavity. Most of the 

 species, being natives of the tropics, require a stove for their 

 cultivation : consequently most of them will be found described 

 in the first part of this work. 



DAVALLIA CANAEIENSIS (From the Canary Islands). This, 

 the well-known Hare's-foot Fern, is too well known to need 

 description. It grows very well in the greenhouse ; but, like 

 many other Ferns, enjoys more heat and moisture when it can 



L.SB. 







