THE CHRISTMAS AND HOLLY FERNS. 169 
Christmas fern. Half the appropriateness of the name 
would be lost if the plant dropped its fronds at the 
beginning of winter. Its name, however, was not given 
because of its presence during the holiday season, but 
because the pinnules are set with bristle-tipped teeth 
which gives them a considerable resemblance to holly 
leaves. That .it loves the cold, is shown by its range 
which extends over the northern parts of both Hemis- 
pheres. In America, its southern limits are nearly 
identical with the northern limits of the Christmas fern, 
as if Nature had assured herself that there should be 
no rivalry, by keeping separate two species so nearly 
alike. 
The holly fern is rather smaller than the Christmas 
fern but in many ways suggests the relationship. Like it, 
the fronds are narrow, lanceolate, once pinnate with 
eared pinnules, and growin circular clumps. They differ, 
however, in the shorter, broader and scythe-shaped 
pinnules, in the basal ones being reduced to small green 
triangles and in producing sori on the backs of ordinary 
fronds. The pinnules are often so closely set as to over- 
lap and the margins are sharply toothed. The stipes 
are also shorter. The sori are confined to the upper 
part of the frond and are arranged on the pinnules in 
two rows midway between the margin and the midrib, 
and also on the eared bases. 
This species is found in most of British America, being 
rarest in the Southeast. It doesnot occur in the Eastern 
United States but is found sparingly in Wisconsin, and 
in the West extends as far south as Utah and California. 
It is a lover of the rocks, its favourite dwelling place 
being the talus of broken stone at the base of shaded 
cliffs. 
