17 . 
THE ALPINE POLYPODY. 
Pohjpodium alpestre. 
Plate 9, Fig. 2, Page 301. 
It was not until the year 1841, that this Fern was discovered 
and added to the list of the British flora ; it having been 
previously overlooked or mistaken for a variety of the Lady 
Fern (Athyrium Jilix-foemina) . Since its discovery, British 
botanists have been engaged in discussions as to the position 
which it should take amongst the species of our native Ferns. 
Some of them think it should rank as a variety of the Lady 
Fern, whilst others, and these the majority, include it amongst 
the Polypodies. If the character which has originated the 
name Polypodium , — ‘many footed,’ — were regarded as the 
distinguishing mark of that genus, this Fern could not be 
included within it. But the distinguishing mark in the 
genus Pohjpodium is the absence from above the circular 
clusters of spore cases of indusia ; and as the spore cases 
in the Lady Fern have very distinct indusia, and the present 
species is without these coverings, whilst the grouping of 
the spore cases into little round heaps closely resembles the 
arrangement in the Polypodies, it is clear that there is good 
ground for including this species under the genus Pohjpodium. 
Under cultivation, it appears that some plants of Polypo- 
dium alpestre have been discovered to possess something like 
indusia covering their sori. These, however, have been in 
such cases regarded rather as abnormal developments of the 
