FERNY COMBES. 
79 
The other Folypodiums which, though found in 
the British Isles, are as yet unknown in Devon, 
are, first, P. aljpestre , which so greatly resembles 
Athyrium Filix-foemina as to have been for many 
years mistaken for it, being distinguished by the 
round masses of seed ; hitherto it is only known as 
growing in Scotland. Secondly, P. Fobertianum or 
calcareum , which, as far as our experience goes, is 
not found in Devon; it somewhat resembles P. 
Dryojpteris , but is erect instead of drooping; both 
stem and fronds of a pale green colour, mealy in 
appearance from minute glands with which the 
whole plant is covered, giving forth a pleasant 
scent when the hand is passed over the fronds. 
P. Fobertianum flourishes in limestone districts: 
Cheddar, in Somersetshire, is one of its habitats. 
Polystichtjm. —Masses of seed round ; indusium 
round , attached by its centre. 
Polystichtjm aculeattjm. Frickly Shield Fern. 
Prond lance-shaped, twice divided; pinnules 
joined to the midrib by their base, which is very 
much narrowed, slightly auricled, that is, enlarged 
on the side next their midrib ; whole plant rigid 
and prickly, dark green, two or three feet high; 
frond narrowed at the base; stem clothed with 
broad chaffy scales. 
