250 CKYPTOGAMIA. FILICES. 



Fronds simple, pinnatlfid, or more or less numerouslj' 

 compounded. 



Species. 1. F. v:d£-are. 2. virginianum. 3 incanum. 

 Pluk. Phyt. t. 289. f. 1. 4. hexagonopterum. 5. cennectile . 

 6. calcareum. 



818. AYOODSIA. R. Brown. 



Sort roundish, scattered. Indusium caliciform, 

 open, with acrinitc margin, including the pedi- 

 cellate capsules. 



Habit that of the preceding genus. 

 Species. 1. W. hyperborea. 2- ilvensis. Both species 

 also indigenous to Lurope. 



319. ASPIDIUM. Swartx. (Shield-fern.) 



Son roundish, scattered. Indusium umbili- 

 cate or opening on one side. 



SpBciES. 1. A. cicutarium. 2. acrosUchoides- 3. novebo- 

 racense. 4. Thelypteris. 5. cristatum. 6. obiumm. 7. aeu- 

 hatum. 8. mar^rinale. 9. Fihx mas. 10. intermedium. 11. 

 spinulosiim. 12. dilatatum. 13. bulbiferum. 14. asplenioides. 

 15. Filix femina. --IQ. ang^istum. \7' punctilobiim. 18. a?o- 

 mariu7n. 19. tenue. 20. rujidulurru 



820. ONOCLEA. L. (Sensitive Fern.) 

 Capsules densely covei'ing the back of the 



frond. Lidusia squamiform, connate in the 

 form of berries and not expanding.. 



sterile fronds deeply pinnatifid, fertile ones bipinnately 

 divided. 



Spectes. 1. O. sensibilis. 2. obtiisilobata. — A North 

 American genus. 



821. STRUTHIOPTERIS. Willd. 



Capsules densely covering the back of the 

 frond. ladusia sq^uamiform, marginal, opening 

 internally. 



Nearly allied to the preceding genus. Fronds bipin- 

 Hatifid. 



S?ficiES. 1, S pennsylvanica. A genus scarcely distinct. 



