THE CLIFF BRAKES. 85 
next to appear are eared at base and in those that fol. 
low, the ears grow more distinct until they become sep- 
arate pinnules. One fancies that all the pinnules of a 
large frond were successively cut off from the terminal 
one in this way. 
The fronds remain green through the winter, the 
leathery texture of the blades enabling them to endure 
the cold, while the rootstock, which is frequently on the 
surface, is warmly wrapped in its protecting scales. 
When the fronds die, the pinnules drop from the rachis 
leaving the new growth surrounded by an_ unsightly 
tangle of dead stems. 
From the colour of the blade this is often called the 
blue fern, while the colour of the stipe has suggested the 
specific name atropurpurea as well as the common one of 
purple-stemmed cliff brake. 
The winter brake is found in suitable situations from 
British America to Georgia, Northern Mexico and Cal. 
ifornia. Its natural habitat is rocky ledges, though it 
occasionally grows upon the masonry of bridges and 
other structures. Notwithstanding its predilection for 
limestone, it thrives in cultivation in any good soil if 
not kept too wet. A fruiting pinna of this species is 
shown in the Key to the Genera. 
The Slender Cliff Brake. 
The slender cliff brake (Pellea gracilis) is even more 
closely associated with the limestone than its relative. 
There appears to be no record of its having been found 
on any but rocks of this character. In southern New 
York it grows on shales that contain but a small percent- 
age of lime, which seems to be as far as it ever gets from 
