84 THE CLIFF BRAKES. 
The Winter Brake. 
Those who dwell in other than limestone regions, have 
not a very good chance of finding the winter brake 
(Pellea atropurpurea) at home. It is not entirely con- 
fined to calcareous rocks, but its occurrence upon other 
kinds is sufficiently rare to be noteworthy. Next to 
limestone, its preference is for sandstone, though even on 
limestone it is peculiar in its choice of situations and is 
common only here and there. It seems impatient of 
deep shade and not very particular as to moisture, in this 
showing one of the bracken’s traits. It often thrives on 
dry cliffs in full sun. 
Several things combine to make the winter brake a 
striking species. Especially is this so in regard to the 
colours it displays. The short creeping rootstock is 
covered with hairlike, bright brown scales, the stipes are 
dark, purplish brown and the fronds are bluish green, 
quite unlike the hue of ordinary species. 
The blade is about as long as the stipe, the whole frond 
measuring from four to eighteen inches in length. In a 
general way the blade may be described as twice pinnate 
below, grading upward to the pinnate apex, but it is 
noted for its irregularity. Small fronds may be twice 
pinnate and larger ones simply pinnate; an entire pinna 
may stand opposite a pinnate one; one side of the 
secondary rachis may bear lobed pinnules and the other 
entire ones, while eared and forking pinnules are com- 
mon. In sterile fronds the pinnules are oval or elliptical, 
but the fertile, which are somewhat taller, have broadly 
linear pinnules, due to the fact that part of each margin 
is reflexed to form the broad indusium. The infant 
fronds are undivided and nearly circular in outline, the 
