IJJ
records it, on the authority of Dr. Young, as occurring at Dun-
doiiald, near Paisley, and at the Carse of Gowrie, ou that of
Mr. James Macnah, Curator of tlie Horticultural Society’s E x perimental
Garden at Edinburgii : in this country it scarcely ever
occurs in its natural habitat, the dry fissures of rocks ; Dovedale,
in Derbysliire, Cheddar, iu Somersetshire, and a rock on
the road between Caernarvon and Bangor, are the only three
instances in wliich I have positively ascertained that it grows in
sucli situations. I t has apparently become naturalized in tlie
mortar of our walls and ancient buildings, where it selects
the dry parts, and if the lower portion of the walls he wet, it
eschews it altogether.
I he roots are short, hut possess a remarkable power of penetrating
the mortar ; they are of a brown colour, and somewhat
scaly : the rhizoma is tufted, brown, and scaly : the young
fronds make their appearance in May and June, arrive at perfection
in August, and continue green throughout the winter ;
they are always fertile.
A small portion only of the rachis is naked, and is beset more
or less thickly with pointed chaffy scales : the form of the frond
is linear, elongate, and pinnate or pinnatifid : the pinnæ are
attached to the rachis hy their entire base, and are sometimes
also connected with each other ; they are obtuse, rounded, and
crenate ; the entire under-surface of the frond is covered with
brown pointed scales, which have been thought in many respects
analogous to the indusium of other ferns.
The lateral veins are few in number, alternate, and irregularly
branched ; they terminate before the margin of the pinna, and
are united or anastomose at their extremities, dividing the
pinna into a number of compartments. The anterior branch of
every lateral vein bears an elongate mass of thecæ, which, unless
we consider the scales as analogous to an indusium, are perfectly
naked. These thecæ appear to me to he attached to the back
of the vein, and to he forced aside hy the mode in which they
are pressed by the surrounding scales. In many fronds I find
a mass of thecæ attached to a lateral vein, which in each pinna
runs parallel with the rachis ; Mr. Smith, of Kew, considers
that, in this mass, the thecæ are so attached as to point towards
the rachis, while those of other masses point towards the midvein
: in examining a great number of specimens I certainly
find these have an inclination in tlie way alluded to hy Mr.
Smith, hut I consider tliis to arise from tlie pressure of the
scales, for, in our British Ferns I have observed tliat when the
indusium is entirely absent, tlie thecæ are not naturally attached
to either side of the vein, hut to its back. In the pinna from
which I have made the drawing shewing the veins, this mass
near the rachis did not exist.
I find that Mr. Smith was aware of the anastomosing veins of
Ceterach, a very obvious and distinguishing character; hut to
the best of my belief no author has alluded to it. I observe
that Presl places Ceterach in the genus Gymnogramma, in which
all the veins are free and unattached at their extremities—indeed
he makes this a distinguishing character of the genus, I cannot
help thinking that the genera Gymnogramma and Grammitis
are separated on characters really too trivial to notice.
Dioscorides (lib. iii. p. 234) greatly extols the medicinal
virtues of this humble fern ; he recommends a decoction of it to
be taken in wine during the space of forty days ; it is not quite
a universal panacea, but its powers seem very comprehensive
; amongst other qualities he asserts that “ cálculos vesicæ
comminuit. The same author alludes to its similarity to the
animal called Scolopendra, a comparison which almost every
author institutes, hut the resemblance is not very manifest.
The cut below represents a more usual form of Ceterach
officinarum than that at p. 85 ; the difference will be found in
the less complete separation of the pinnæ.