This very beautiful plant exists only in the immediate
neighbourhood of waterfalls, and in situations where a constant
moisture is maintained. This is, indeed, quite necessary
to it, on account of its semi-membranous texture,
which shrinks before an arid atmosphere ; and hence it can
only be successfully cultivated when kept quite close, and
constantly wetted over-head. This species has a creeping
stem, smallish, wiry, and black-looking, clothed with
pointed scales. The fronds are three or four times pinnatifid,
cut up into small linear segments, which are entire or bifid
at the apex, and have a stout nerve or vein running up their
centre, and rendered very conspicuous in consequence of the
thin pellucid texture of the leafy expansions which surround
it. Or the frond may he described as consisting of a series
of three or four times branched rigid veins, margined
throughout by a thin, pellucid, cellular expansion, or wing,
a greater or less number of the apices of the veins becoming
surrounded by the cellular membrane in the form of an urn
or vase, and within them bearing the fructification.
The fronds are pendulous, and vary from an angular-
ovate to a lanceolate form, the divisions being considerably
undulated, so that they acquire a crisped appearance. The
first series of lobes are usually of an ovate-lanceolate form ;
the next series shorter, more ovate, and the third series of
divisions narrow, more or less hnear. The ultimate branches
of the veins which extend into the divisions of this third
series, end just at or within the apex of the lobes if they are
barren; but if they are fertile, they are produced beyond
the margin, and surrounded at the base by the urn-shaped
involucre, within which the spore-cases are placed. Sometimes
the involucre is so placed as to appear immersed
within the margin, but it more frequently projects beyond
the margin. There is also considerable variation as to the
length to which the bristle-like receptacle is extended
beyond the involucre; sometimes scarcely exceeding it in
length, and sometimes being four or five times as long.
The lanceolate form of this plant has been sometimes
thought distinct from the broader form, but the general
opinion is, that it is an extreme variety of the same species;
to this the name of Andrewsii is applied, in compliment
to the gentleman by whom it was first discovered.
The Sister Isle now claims, so far as the British Isles are
concerned, sole parentage of this lovely, half-transparent
species. There, amidst dripping rocks, it thrives with a
degree of luxuriance which charms every one who has seen
it creeping over their shelving ledges. It is said to have
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