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 (Pellcea 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 



