Polypodium Dryopteris, Linnceus. 
Gymnocarpium Dryopteris, Newman. 
OAK FERN. 
Roots — Radicles black and wiry : rhizome black, slender, 
and creeping. 
Frond — Often drooping, nearly triangular, tliree-branched; 
each branch pinnate, the pinnae opposite. 
Stipes — Twice the length of the frond, very slender, 
and smooth to the touch (especially when compared with 
P. Calcareum) ; a few straggling scales at the base. 
Pinnae — Opposite, pinnate at the base, and pinnatifid 
towards the end ; apex sub-acute. 
Pinnules — Oblong, somewhat serrated, round at the 
apex ; the basal pinnules are sessile. 
Venation — Costae sinuous; lateral veins both simple and 
forked, extending to the margin. 
Fructification — Clusters of capsules scattered, circular. 
Habitat — In moist shady places. Found near Rowsley, 
Ashover, &c., on sandstone. 
8 
