penetrate deeply in the hog, while the rhizoma spreads widely
and horizontally, hut never penetrates far below the surface.
The fronds are both barren and fertile. The barren fronds
rise from the bog in May, the fertile ones in July : they both
disappear with the first frosts of winter. The frond is lanceolate
and pinnate, the lowermost
pinnæ are shorter than the
third and fourth pairs ; they
are attached by their stalk
only : about one-third of
the rachis is without pinnæ ;
the pinnæ are pinnatifid, the
pinnulæ rounded, and always
entire : the whole plant is
erect, very slender, delicate,
and fragile ; it is of a pale
green colour ; in size, it varies
from that of the frond represented
in the annexed cut, to
at least four times the size :
the fertile fronds are larger,
and of stronger growth than
the barren.
The lateral veins are alternate,
they are forked almost
immediately on leaving the
midvein, and each proceeds to
the margin of the pinnula ;
each bears a circular mass of
thecæ almost immediately after
the fork ; the lower detached pinnula exhibits the veins and the
attachment of the thecæ ; the upper detached pinnula shews
the thecæ situ on one side, and on the other the margin
of the pinnula (which is attenuated, paler, and convolute,)
covering the thecæ : between the rhizoma and the pinnula,
shewing the veins, is a fertile pinna, seen from above ; the
pinnulæ being narrower to appearance, owing to the convolute
character of their margin. Each mass of seeds has, in an early
state of the plant, a small suhreniform indusium attached on one
side to the vein, at the point to which the stalks of the thecæ
are attached. This is shewn at the top of page 45.
MOUNTAIN EERN.
L a s t r s e a O r e o p t e r i s .—Presl.
Aspidium Oreopteris.—Swartz, Smith, Hooker, Galpine, Mackay,
Francis.
Aspidium odoriferum.—Gray.
Polypodium Oreopteris.—Withering.
Polypodium fragrans.—Hudson, Berkenhout.
Polypodium Thelypteris.—Bolton.
l o c a l it ie s .
E n g la n d . . . In the northern counties very common; Shropshire, on the Clee H ill; Derbyshire
near Matlock; Nottinghamshire, near L in b y ; Northamptonshire; Herefordshire,
a t Amestrey quarry and Shobdon P a rk ; Oxfordshire; Wiltshire, not
common; Somersetshire; Sussex; Kent, Tunbridge Wells, Blackheath; Essex,
Epping F o re st; Middlesex, Hampstead Heath ; Norfolk.
W a l e s . . . . In North Wales abundant on all the mountains ; in Radnorshire, at Water-break-its-
neck, covering acres of the m ountain; Brecknockshire; Merionethshire; Cardiganshire
; Glamorganshire.
Scotland . . On all the mountains.
I r e l a n d . . . County Londonderry, Muff Glen and Glen Roe; County Donegal, vicinity of
Milroy Bay; County Kerry, near Muckruss sparingly, and very slender; (is this
the Thelypteris of Mackay!) County Wicklow, at Glendalough, m ost abundant.
T h i s fern, as its name implies, is an inhabitant of mountains,
and is rarely found in low situations, or cultivated districts. I t
is particularly abundant in the Highlands of Scotland, in many
districts completely taking the place of Pteris Aquilina. I t also
abounds in the hilly parts of Northumberland, Durham, Cumberland,
Westmoreland, Yorkshire, and Lancashire, and again in
1
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