Polypodium Dryopteris, Linnaeus. 
Gymnocarpium Dryopteris, Newman. 
OAK FERN. 
Root — Radicles black and wiry; rhizome black, long, 
and creeping ; much thinner than in the Polypodium 
vulgare. 
Frond — Nearly triangular, three-branched; each branch 
is pinnate, the pinnse are opposite. 
Stipes — Twice the length of the frond, very slender, and 
smooth to the touch (especially when compared with the 
P. Calcareum ) ; there are a few straggling scales at the base. 
Pinnas — 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 — Midvein sinuous; lateral veins, both simple 
and forked, extending to the margin. 
Fructification — Clusters of capsules marginal. 
Habitat — In moist, shady places. Found near Rowsley, 
Ashover, &c., on sandstone. 
7 
