the stems thus penetrating to a depth of fifteen feet. This
caudex is thickish, black-looking, and succulent, containing
a good deal of starch. Prom it are produced, at intervals,
the annual fronds, which generally make their appearance
about the latter end of May, when there is little risk of
frosts, for the least frost would destroy them, and, indeed,
it is not uncommon for the earlier growth to be destroyed
in exposed places by the very slight frosts which occur at
that season of the year. The fronds themselves have been
variously described, and often erroneously, for they are not
unfrequently said to be three-branched, a form which really
occurs in one of the smaller Polypodies {P. Pryopteris).
Now, they are not properly three-branched, and except when
very much starved and stunted, do not approach that form
very nearly. They are, in reality, bipinnate, or when very
luxuriant tripinnate, the pinnæ standing opposite in pairs,
each pair in succession becoming fully developed, while the
main rachis is extending upwards, and the next pair is beginning
to unfold. The mature fronds are thus truly hi- or
tri-pinnate, with the pairs of pinnæ standing opposite.
When the fronds are much diminished in size by the sterility
of the soil which sustains them, they become almost triangular,
and then have somewhat the appearance of a threebranched
frond, the development of the lower pair of
branches not leaving the plant energy enough to carry up
its rachis, and produce the other pairs of pinnæ which it
would normally possess. That this is the true habit of the
species is still more clearly exhibited when it attains its
greatest luxuriance, for the full-grown fronds then consist
merely of a series of pairs of branches from the bottom to
the top. The unrolled young fronds are very curious objects,
and the watching of their development will be found
full of interest.
The stipes is downy while young, and furnished with
sharp angles when mature, which, if it be incautiously
pulled, will wound the hand severely. The part under
ground is black, like the creeping stem itself, and is spindle-
shaped just at the base, where it permanently retains the
downy or velvety surface which was present in the upper
portions while young.
Average specimens of the fronds are tripinnate, that is,
they produce a certain number of pairs of branch-like pinnæ,
which branches are bipinnate. We must confine our further
description to one of these branches, selected from the
lower part of the frond, where they are more perfectly developed
than in the upper parts— such a branch, in fact, as is