KEY TO THE GENERA 



Froit dots elongated, borne in 

 chain-like rows parallel to 

 the midribs of the pinnae 

 and lobes, opening on the 

 side next to the midrib; 

 large^ water-loving species. 

 Chain Ferns. 



WooDWARDiA. lis 



Fruit dots roundish, indusium 

 fixed by the center; ever- 

 green. Christmas Fern ; 

 Holly Ferns. 



POLYSTICHUM. 80 



Fruit dots roundish, indusium 

 roundish or kidney-shaped, 

 attached at the base of a 

 notch. Shield Ferns. 



AspiDiuM. 90 



Aspidium. 



Cystopteris. 



Fruit dots roundish, indusium 

 hood-like, attached by a 

 broad base and arching 

 over the sporangia, opening 

 on the side toward the apex 

 of the lobes, soon wither- 

 ing. Bladder Ferns. 



Cystopteris. 



164 



