52 Our Native Ferns. 



Tribe II. Polypodies. ( i genus — Polypodiuni, in- 

 cluding Fhegofiieris.) 

 Tribe 12. Grammitides. ( ii genera — Nolholizna, 



Gymnogramme^ Vittaria.) 

 Tribe 13. AcROSTiCHES. (2 genera — AcrosHchum.) 

 Sub-Order III. Osmundaces. (2 genera — Osmunda.) 

 Sub-Order IV. SchizsacE/E. (5 genera — Schizcea, Anei- 



niia, Lygodium.) 

 Sub-Order V. Marattiaces*. (4 genera.) 

 Sub-Order VI. Ophioglossace/E*. (3 genera — Ophio- 

 glossum, Botrychium.) 

 105. It will thus be seen that the fern world comprises 77 

 genera. Other authors, narrowing the limits of generic charac- 

 ters, recognize a greater number. Smith, for example, publishes 

 220, and Presl 230, yet the tendency among most botanists 

 is to restrict the number. While many of our leading systema- 

 tists differ in minor point of classification, there is a general agree- 

 ment in all these attempts at a natural system, which is the end of 

 all classification because founded on morphological resem- 

 blances. 



*Not recogDized by this aiithor aa ordei'S. 



