KEY TO THE GENERA 



PAGE 



B — Sporangia in a contin- 

 uous line along the mar- 

 gins of the pinnules, the 

 indusium formed by the re- 

 flexed edges; fronds large. 

 Brake. 



Pteris. 



60 



Pteris. 



Adiantum. 



Sporangia marginal, borne 

 at the ends of the veins, 

 the indusium formed by the 

 reflexed tips of the lobes 

 of the pinnules; pinnules 

 have no midrib, veins 

 springing from the base or 

 from the lower margin; 

 stipes dark. Maidenhair. 



Adiantum. 138 



Pellaea. 



Sporangia marginal, indusium 

 broad, nearly continuous, 

 formed by the reflexed 

 edges of the pinnules ; 

 fronds smooth, stipes dark ; 

 rock species. Cliff" Brake. 

 Pellaea. 



62 



