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1IY.MEN0PIIYLLUM WXLSO.M. 
HYMENOPHY'LLUM WILSO'NI. 
This owes its specific name to being first distinguished 
from Hymenoj/hyllum Tunbridgense by Mr. W. Wilson. 
It is called H. unilateral by some botanists, in allusion 
to the lobes of the leaflets being on one side. We 
believe it to be the variety of H. Tunbridgense described 
by Bolton as having its “fructification on naked fruit- 
stalks,” and which he found on rocks under Dolbadem 
Castle, near the lake of Llanberris, and on the rock 
called Foal-foot, on Ingleborough, in Yorkshire. 
Root thread-like, brown, slightly scaly, creeping, and 
producing a few fibrous rootlets. Fronds from one to 
three inches high; stalk stiff, smooth, round, winged at 
the top. Leaflets clothe two-thirds of the stalk, dark 
green, alternate, bent-back, lobes curved downwards, 
and spreading horizontally rather than vertically as 
they do in H. Tunbridgense; lobes oblong-oval, sharply 
toothed, and on tho upper side of the leaflet only. 
Fructification is placed as in H. Tunbridgense, but 
unlike that is stalked; its outer case ( involucre ) is 
egg-shaped, with swollen convex valves meeting at 
their edges. The fructification curves forward in a 
direction opposite to that in which the lobes of the leaf¬ 
lets are curved. 
In England it has been found near the waterfall 
above Ambloside; at Black Rocks of Great End, in the 
Scawfcll Range, and at Scale Forco near Buttermere; 
and at Greenfield near Saddleworth, and uear Silverdale. 
