w
i
N
fronds are few in number, they rise early in spring, and disappear
K before winter. The figure of the frond is
linear, its position remarkably erect, and
much more than a third of the rachis is
naked : towards the base it has a few scattered
chafiy scales. A remarkable character
of this species is the propensity of the frond
to decay and turn brown in spots ; this is
more particularly observable towards the apex
of the frond and pinnæ. The fronds are
pinnate ; the pinnæ, which are attached by
their stalks'only, are distant, very short, nearly
triangular, and pinnatifid, the pinnulæ being
serrated. The fronds are fertile and barren,
the former are nearly twice the length of the
latter.
The lateral veins in the pinnulæ are many-
branched, and the anterior branch bears a
circular mass of thecæ, about half-way between
the midvein and margin. The masses
are covered by an indusium, which often remains
«w síím after the seeds are fully ripe: it is
reniform or attached at a lateral point, which,
as the indusium shrivels, and the thecæ swell,
is forced into the centre of them, and so
appears to he orbicular, and attached centrally,
as in the genus Polystichum. Sir J. E.
Smith does not seem to have been aware of
this structure, or of the importance of observing
the characters of the indusium; his
description of the indusium of cristata would
makeita Polystichum, while Lonchitis, “ with
anotch on one side,”would become aLastræa.
This carelessness is more particularly to he
regretted, because compilers unhesitatingly
copy, and thus perpetuate, these errors.
Mr. Beevis tells me that he found this rare fern near the
windmill, on Wimbledon Common : if this he the case, I am
inclined to think it must have been planted there. Many
botanists have industriously sought for it in this locality, but in
vain.
TH E R IG ID FERN.
L a s t r a sa r ig id a .—Presl.
Nephrodium rigidum.—Don.
Aspidium rigidum.—Schkuhr, Hooker, Francis.
L O C A L IT IE S .
E ngla n d . . Yorkshire, foot of Ingleborough, rocks near Settle.
W a l e s . )
I r e l a n d . > Unknown.
Sco tland. )
T h is is another species unknown in this country, except in
the two habitats above recorded. As far as I am able to judge,
the Settle plant agrees exactly with the figure given by Schkuhr
in his Kryptogamische Gewächse, PI. 38, and, unwilling as I
am to admit continental species on the mere coincidence of form
in a casual frond, I must acknowledge that the specimens of
rigidum gathered near Settle by Mr. Tatham, and obligingly
presented to me for this work by Mr. D. Cooper, appear to he,
beyond a doubt, the species in question. The Rev. Mr. Bree has
kindly transmitted to me specimens of his plant, gathered
in 1815 on Ingleborough, near the foot of the mountain,
towards the neighbouring village; when cultivated, it assumes
a more diffuse and lax appearance, and is not so like Schkuhr’s
figure as the plant from Settle. I have the weighty authority
of Professor Don to support me in the opinion that this
species is identical with the Aspidium rigidum of Schkuhr.
This plant was first mentioned as a British species by Dr.
Hooker, in the Supplement to the English Botany, PI. 2i24,
under the name of Aspidium rigidum ; it was next published by
Professor Don, in the Transactions of the Linnean Society of
London, Vol. xvii. p. 435, as Nephrodium rigidum; and, lastly,
by Mr. Francis, in his “ Analysis,” p. 33, and figured PL ii.
fig. 10: the figure, which, as a drawing, is very elegant, appears
rather to be a representation of Filix-mas than the present species.