84 THE CLIFF BRAKES. 



The Winter Brake. 



Those who dwell in other than limestone regions, have 

 not a very good chance of rinding the winter brake 

 (Pellcea 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 



