ï
ii: fH;
’ .f I:
01
tremity, and in those which are larger and more compound,
branched, with a sorus on the lower branch. The fructification
is very unequally produced in different seasons and
localities, being sometimes crowded, and at other times very
sjiaringly scattered over the fronds.
P. Dryopteris is not an uncommon species, hut it occurs
only in mountainous situations and the drier parts of damp
woods : in England mostly in the north ; in Scotland distributed
pretty generally; very rare in Ireland.
This species has been called Polystichum Pryopteris and
Lastrea Pryopteris.
P o l y po d ium P h e g o p t e r is , Linnceus. The Beech Polypody,
sometimes called Mountain Eern. (Plate II. fig. 2.)
This is a somewhat fragile plant, enduring no longer than
till autumn, or the appearance of the first frosts. It grows
wild in moist mountainous situations and in damp woods,
often common enough where present, but rather limited in
its range, occurring, however, in England to the southward,
westward, and northward; pretty generally distributed in
Scotland ; but rarely met with in Ireland. It has a slender
hut extensively creeping and slightly scaly stem, producing
black fibrous roots, and, about May, throwing up delicate
hairy pale green fronds, which, when full grown, measure
T
from six inches to a foot in height. The stipes, which is
fleshy and very brittle, is generally twice as long as the
leafy part of the frond ; near its base are a few small almost
colourless scales. The fronds are triangular, extended into
a long narrow point. In the lower part they are pinnate ;
but this distinction of the parts is seldom carried beyond
the two lowest pairs of branches, those of the upper portions
of the frond being connected at the base, in what
is technically called a pinnatifid manner : hence this Eern
is said to be subpinnate, which, in this case, means partially
pinnate, or pinnate at the very base only. The
pinnæ have a narrow and acutely lance-shaped outline, and
are deeply pinnatifid; they usually stand opposite each
other in pairs, the lowest pair being directed downwards,
towards the root, and set on at a short distance from the
rest. The united base of the pairs of the other pinnæ,
when they stand exactly opposite each other, exhibits a
cruciform figure more or less strikingly obvious ; and by
this mark, in conjunction with the subpinnate mode of division,
this species may be known from the other British Polypodies.
The veins in the lobes of the pinnæ are pinnate ;
that is to say, there is a slender midvein, from which alternate
venules mostly unbranched extend to the margin ;