PTERIS AQUILINA 219 



is found. Its fronds (Fig. 255) are deep green, and grow to two or 



three feet long from a caudex, a la Lady Fern, which, as we have 



said, it closely resembles, the chief difference being in the very small 



spore heaps, which, however, despite 



their resemblance to those of the Poly- /jk&$h- 



podium family, sometimes display a 



rudimentary cover or indusium, which 



the true Polypody never does, and 



what is more to the point, some of 



the recognized varieties of Lady Fern, 



the Horsfall plumosum to wit, have Fig ' 2S5 " F ' alJ>estre (pinna) - 



spore heaps of precisely similar nature. Despite its mountain 



habitats, where it grows among the rocks and is often in the 



clouds, it does quite well under culture, treated like the Lady Fern, 



and not allowed to get dry. Several varieties are recorded, viz. : 



Flexile (Plate XXXIII).— A narrow form with short pinnae and 

 more distant pinnules, deeply toothed, very distinct, found on the 

 Cliva Mountains by Mr. Backhouse, and in Ben Lawers by Mr. 

 Donald Haggart. 



Laciniatum (Plate XXXIII). — A distinct form of flexile raised 

 by Messrs. Stansfield ; see illustration. 



Cristatum. — A thoroughbred, pretty cristatum found by Mr. 

 Alex Cowan, of Penicuik, finely tasselled. 



PTERIS AQUILINA (The Common Bracken) 



(Plate XXXVI) 



The Common Bracken is probably the most widely spread species 

 of Fern, since it is found nearly all over the world in more or less 

 modified forms. In this country it covers large areas up to a 

 level of about two thousand feet, monopolizing in many places 

 heaths, commons, and woodlands, and in the latter especially 

 producing immense fronds eight or ten feet long, and, despite its 

 commonness, of great beauty. Its botanical name means the 

 eagle's wing. Fig. 262 shows a colony of a crested form of this 

 species, and is peculiarly interesting as a rare example of a variety 

 extending over a large area to the entire exclusion of the normal. 

 The illustration shows that all the plants are tasselled, and Fig. 261 

 shows the character to be well marked, and also depicts two other 

 abnormal varieties found some fifty yards away on the same ground. 

 In point of fact this Fern varies considerably, and given a fair 

 acreage of it, we may be practically certain of finding three forms, 

 the normal, a much leafier type, and a stiff, leathery, crispy form, 

 much narrowed and of a darker green. The Pteris family, which 

 is a very large one, has its spore capsules arranged in unbroken lines, 

 immediately next the margin of the subdivisions, such margin 



