120 
THE FERN FAMILIES OF BRITAIN. 
of tlie fructification peculiar in the PolypodiuT^ family. The 
Fern by its tough nature is enabled to stand plenty of air, 
and even of sunshine, and we consequently find it at home 
on the tops and in the crevices of old walls, on the roofs of 
old buildings, and cosily nestling amongst moss-grown rocks, 
and similar places where its roots can creep freely about in 
accumulations of leaf mould. We also find it clothing the 
sloping sides of hedge banks, and forming a dense undergrowth 
among the roots of the hedges themselves ; and lastly, but by 
no means leastly, it makes itself a congenial home in the 
mossy bark of old trees, and amongst the debris which 
collects in their forks and other hollows. Good drainage 
and plenty of leaf mould are, it will be seen, the first desi- 
derata of its cultivation. As the creeping rootstocks do not 
burrow, but keep near, or even on, the surface, this fact must 
be remembered in planting. This Fern, simple as it is in its 
normal outline, has given us some most beautifully divided, 
crested, and plumose varieties {vide Plate Y., to which the 
figures in parentheses refer). 
P. V. bifido-cristatum (twice-cleft, crested) (2). A long, 
narrow, robust, crested form, the short pinnse fanned out at 
tips into rounded crests, the frond tip repeatedly divided, 
forming a large, flat tassel. 
P. V. cambricum (Welsh) (9). This, which is commonly 
called the Welsh Polypody, is the true plumose form of the 
species, and is always barren. It has been found wild in 
various places. In this, the ordinarily simple pinnae are so 
wide as to overlap considerably; they are also divided into 
long, saw-toothed divisions. The texture of the fronds is 
much thinner and more delicate than in the normal form, 
and the width considerably greater. A most beautiful form 
indeed. 
P. V. camb. Prestonii (Preston’s). A still more plumose 
form than the last. Wild find. Lake district. 
P. V. cornubiense (Cornwall), Syn. elegantissimum (most 
elegant) (10) ; P. v. Powlerii (Fowler’s) ; and P. v. trichoman- 
oides (Trichomanes-like') {vide Fig. 27). These three are too 
closely akin to be separately described ; they stand in order of 
