WILSON’S FILMY FERN.
H y m e n o p h y l l u m W i l s o n i .—Hooker, Mackay, Francis.
l o c a l it ie s .
E ngla n d . . . Cumberland; Westmoreland,in the lake district, Scaw FeD, Scale-Force waterfall,
Lodore waterfall, waterfall above Ambleside, in ravines near theSkrees, on rocks
in Wastdale, and near Wastwater, Derwentwater, Buttermere, and Winander-
mere ; Yorkshire, near Halifax, Greenfield, and Saddleworth.
W a l e s Caernarvonshire, throughout the Snowdon district, Rhaiadr-y-Wenol, Falls of the
Lugwy, Capel Curig, Rhaiadr Mawr, near Lianberris, Cwm Idwel, NantFrangon,
&c. &c. ; Merionethshire, at Rhaiadr Du, near Maentwrog, and Rhaiadr-y-
Mawddach, near Llaneltyd ; Brecknockshire, near Brecon.
Scotland . . . Abundant in the Highlands ; the localities are far too numerous to detail.
I r e l a n d . . . . Counties Antrim, Londonderry, and Donegal; County Galway, at Maam, Round-
stone, and near Oughterard ; County Kerry, throughout the Killarney district;
County Cork, Glengarriff and Youghal; and County Wicklow, a t Glendalough,
the Hermitage Glen, and Powerscourt Waterfall.
In this, as in the preceding species, I have omitted those
localities which I could not verify by my own observation ; the
present species is most abundant in Scotland, descends through
the northern English, Welsh, and Irish counties, and finally
mingles most abundantly with Tunbridgense, in the southern
counties of Ireland.
The roots and rhizoma of Wilsoni offer no characters hy
which I can distinguish them from those of Tunbridgense ; the
fronds of both are circinate, they make their appearance late in
tlie summer months, and usually remain green through the
winter, turning completely black in the ensuing spring.
The frond consists of alternately-branched veins, clothed with a
membranous wing, the margin of the wings being serrated : the
wing on the rachis is less apparent in Wilsoni than .in Tun-
hridgense ; the pinnæ are always convex above, while those of
Tunbridgense are usually flat : Wilsoni has a more erect habit,
Tunbridgense more horizontal, and, indeed, somewhat drooping,
so that, on the trunk of a tree, the fronds seem to rest one on
anotiier like the tiles of a house. The receptacle is very
different from that of Tunbridgense ; it is elongate, swollen at the
base, and its exterior margin perfectly without serratures : when
the seed is mature, the receptacle opens at the top, and, s p littin g
down the middle, remains widely gaping.
A comparison of the two illustrations, which are drawn with
considerable care, will enable the botanist to form a more correct
idea of the difference between them than I am able to convey hy
any description: they are of the natural size, the detached
pinna of each being magnified.
The Vignette represents a singular Holly-tree at Erwood, on
the banks of the Wye, between the towns of Hay and Bualt, a
district which has hitherto been h u t little investigated hy the
botanists, h u t which appears to me to offer a rich return for a
very moderate labour. The river is very rapid, running through
the most beautiful woods, and over a bed of huge masses of stone.