THE MARSH FERN TRIBE. 
eae “wr 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. 
*_. cluded 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 (A spidium 
Thelypteris). It is one of our commonest species, and al- 
though, as its name indicates, the marsh is its favourite 
