150 HISTORY OF BRITISH FERNS. 



tremity, and in those which are larger and more compound, 

 branched, with a sorus on the lower branch. The fructifi- 

 cation is very unequally produced in different seasons and 

 localities, being sometimes crowded, and at other times very 

 sparingly scattered over the fronds. 



P. Dryopieris is not an uncommon species, but it occurs 

 only in mountainous situations and the drier parts of damp 

 woods : in England mostly in the north ; in Scotland dis- 

 tributed pretty generally; very rare in Ireland. 



This species has been called Polystichum Dryopteris and 

 Lastrea Dryopteris. 



POLYPODIUM PHEGOPTERIS, Lwnaus. The Beech Poly- 

 pody, sometimes called Mountain Pern. (Plate II. fig. 2.) 



This is a somewhat fragile plant, enduring no longer than 

 till autumn, or the appearance of the first frosts. It grows 

 wild in moist mountainous situations and in damp woods, 

 often common enough where present, but rather limited in 

 its range, occurring, however, in England to the southward, 

 westward, and northward; pretty generally distributed in 

 Scotland ; but rarely met with in Ireland. It has a slender 

 but extensively creeping and slightly scaly stem, producing 

 black fibrous roots, and, about May, throwing up delicate 

 hairy pale green fronds, which, when full grown, measure 



