Ill
The lateral veins are forked about half way between the
midvein and margin : after the fork the anterior branch bears a
nemly circular mass of thecæ, which are covered by a smooth,
lead-coloured indusium, reniform, or
attached to the vein at the point
where the stalks of the thecæ are
inserted ; the indusium is more perfect,
conspicuous, and lasting than in any
other British fern ; the veins do not
quite reach the margin of the pinnulæ,
and the anterior is not quite so long as
the posterior.
Although this fern is of very constant
figure, yet it occasionally departs a good
deal from the typical form; a frond
preserved in the herbarium of Mr.
Winch, now in the possession of the
Linnean Society, is simply pinnate, the
margins of the pinnæ being waved, hut
not divided. This variety is precisely
analogous to the lonchitiform variety of
Polystichum aculeatum ; it is not a
seedling, or young plant, being itself in
full fructification, as shewn in the
accompanying figure. Three other
varieties are named by Mr. Francis,
viz., 1. Variegatum. White-tipped,
and edged with green. 2. Recurvimi.
Pinnæ crisped, turned down; frond
small, rachis smooth. 3. Spinosum.
Pinnules serrate, smaller blended together,
larger auricled.
Much has been said of the value of the rhizoma of Filix-mas
as a vermifuge, and formerly it was employed in this capacity
somewhat extensively: the result of my inquiries on the subject
is, that it has long ceased to he an article of any commercial
importance.
TH E CRESTED FERN.
L a s t r je a c r is t a t a .— Presl.
Aspidium cristatum.—Smith, Hooker, Galpine, Gray, Francis,
(not of Mackay.)
Pohjpodium cristatum.—Linneus, (not of Berkenhout, Lightfoot,
nor Hudson.)
LOCALITIES.
E n g la n d . . Nottinghamshire, Oxton-bogs, near Nottingham; Norfolk, among fu rze at Holt
heath, and by the side of a drain on Fritton-broad.
W a l e s . )
Scotland. > Unknown.
I r e l a n d . J
A l t h o u g h Lastræa cristata has occurred so very sparingly in
this country, it is not difficult to form an opinion of its value as
a species : our English plant corresponds precisely with the
Polypodium cristatum of Linneus, as now preservedin the Linnean
Herbarium. There is scarcely a species which has remained
during a series of years so completely local. The fronds, said
by Smith to have been gathered on hogs amongst alder hushes, at
Westleton, Sufinlk, by Mr. Davy, I have never seen ; and I fear
that some mistake has, in this instance, crept in, either as to the
plant, or the habitat. Mr. Smith, of Kew, has a frond labelled
Leicestershire, hut I believe nothing more is known on the
subject, so that I fear to record that county as an undoubted
habitat of the species. I am indebted to Mr. Samuel Woodward
for the loan of specimens gathered by Mr. Wigham, on Fritton-
hroad, Norfolk, a habitat which I think has not been previously
recorded; and those from Holt-heath and Oxton-hogs I have also
seen and carefully compared.
The root of Lastræa cristata is brown, short, and not firmly
fixed in the earth ; the rhizoma is tufted and rather chaffy : the
J I