THE CHRISTMAS AND HOLLY FERNS. 



OWEVER much we may admire the 

 summer species, we can scarcely 

 fail to have a higher regard for 

 those sturdy ferns that remain 

 through cold and snow to make the 

 woodlands and thickets less dreary. 

 For the most part they are among 

 our coarsest species delicate fronds 

 have little chance against the frost 

 and for this reason are likely to 

 be overlooked or neglected in a 

 milder season. But when in dark and stormy weather 

 the green fronds wave us a welcome from icy ledge or 

 snowy thicket, the day seems suddenly to brighten. 



Foremost among our winter species must be placed 

 the members of the Polystichum family. These are often 

 classed with the wood ferns in the genus Aspidium or Dry- 

 opteris. The wood ferns indeed are their nearest relatives, 

 but there is this important difference between them : in 

 the Polystichums, the sori are round and covered with a 

 circular indusium which is fixed to the frond by its de- 

 pressed centre; while in the wood ferns, the indusium is 

 usually reniform and attached to the frond by the sinus. 

 Like the wood ferns these species are sometimes called 

 shield ferns and buckler ferns. 



