THE MARSH FERN TRIBE. 



N Eastern America, two families of 

 ferns divide nearly half our species 

 between them. One of these is 

 known as the- genus Aspidium or 

 Dryopteris, the other as Asplenium. 

 As the genus Aspidium has been 

 understood in America, it has in- 

 eluded a diversity of forms, some of 

 which have but recently been re- 

 moved to the genus Polystichum. 

 Those that -remain fall very natur- 

 ally into two divisions as regards 

 form and habitat, and to the smaller 



of these, of which the marsh fern may be taken as 

 the type, we have for convenience given the title of 

 the marsh fern tribe. The species have a strong family 

 resemblance almost too strong, the young student may 

 be inclined to say when he comes to study them but 

 a little study will soon fix the characters of each in the 

 mind, after which they may be distinguished at a glance. 



The Marsh Fern. 



Any one who has visited a bushy swamp in the north- 

 eastern States, where alders, button-bushes and cat-tails 

 flourish, has doubtless seen the marsh fern (Aspidium 

 Thelypteris). It is one of our commonest species, and al- 

 though, as its name indicates, the marsh is its favourite 



