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51. I
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RUE-LEAVED S PLEENWORT.
A s p l é n iu m R u t a -m u r a r ia of Authors.
Asplénium murale.—Gray.
Asplénium germanicum.—Willdenow. (
Asplénium altemifolium.-—Wulfen, Smith, Francis. ’
L O C A L IT IE S .
E n g la n d , 'j
Universally distributed.
I r e l a n d , j
T h e Wall Rue, or Rue-leaved Spleenwort, is one of those
plants, which, like our half-domesticated birds, the sparrow, the
swallow, and the martin, seem to have deserted their native
wilds, and to have taken up their residence amongst the habitations
of men. I t is abundant on ruins and on old churches,
walls, and bridges, and this equally whether they he built oi
brick or stone ; although Ray * asserts, and subsequent authors
have repeated, that when it gets upon burnt bricks, it dies : this
misstatement must, I think, have arisen in the first instance from
a slip of the pen, or, perhaps, a misprint, and not from a hasty or
incorrect observation; for so carefully observant a man as Ray
must have frequently seen it flourishing in the crumbling mortar,
filling the interstices of brick buildings ; we need wander no
further from London than the wall of Greenwich Park, and here
it will he found abundantly on the brick, but very rarely on the
stone. Throughout the northern, western, and southern
counties of England, and also in Wales, Scotland, and Ireland,
this fern is to he found on almost every ruin. In a perfectly wild
state, it grows abundantly on the rocky hills in Scotland, particularly
on Arthur’s Seat, near Edinburgh ; in the Peak district
of Derbyshire ; on Cader Idris, and Snowdon sparingly.
The roots of Asplénium ruta-muraria are vriry and black ; the
rhizoma is black, tufted, and clothed with bristly scales : the
fronds make their appearance in May and June, arrive at
maturity in September, and continue perfectly green throughout
the winter, and until the ensuing May ; they are always fertile.
* The assertion is only in the 3cl Edition, edited hy DiUenhi.s.
m \
The rachis is black, or dark purple, very smooth and shi
and for more than half its length, naked.
The normal form of the frond is triangular
./I
and pinnate, the pinnæ being
alternate, and also pinnate ; the pinnulæ
are of varied form, but mostly somewhat
triangular or lozenge-shaped ;
their exterior margin is generally
serrated.
The veins radiate from the stalk to
the exterior margin of the pinnula,
and to these are attached the elongate
linear masses of thecæ, two, three,
four, and even five on each pinnula;
these are at first covered hy an elongate,
linear, white indusium, which is
pushed aside hy the growing thecæ,
turned back, and finally lost, the hack
of the pinnula becoming eventually
covered hy a dense brown mass of
thecæ.
A very remarkable form of this plant
has been found in several localities in
Germany, Hungary, and Scotland ; by
many botanists this has been considered
a species, under the name of Asplénium
germanicum, or A. altemifolium. A
representation of this plant, which I
would propose to name the alternate
type of A. ruta-muraria, is given at
f3¡3 : the form of the frond is elongate
and pinnate ; the pinnæ are distant,
small, linear, alternate, and generally
notched or divided at the apex. Above
the two singular plants ¡3¡3 I have
figured a third, with three dissimilar
fronds ; this was gathered at Arthur’s
Seat, near Edinburgh, in 1838. I have
introduced this, as forming a connecting
link between the normal type of the
ill f f i ;v
(/
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plant represented above and the alternate type below; and I think
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