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XVI. HYMENOPHYLLUM. 
the rachis being also terete in the lower part, and slightly 
winged above. The pinna are convex above, or recurved 
no as to appear sub-unilateral, the involucres being usually 
curved in an opposite direction ; they are wedge- 
shaped in outline, digitate- 
pinnatifid, the segments 
being linear obtuse, and 
spinulosely serrate along 
the margins. The fructi- 
fication is in this species 
also axillary ; but the re- 
ceptacle is surrounded by 
an involucre of two oblong 
convex or inflated valves, 
touching only by their 
edges, which are quite 
entire. In its texture 
and colour the plant is 
very similar to the Hyme- 
nophyllum tunbridgewe ; 
in both, the young fronds 
are produced towards the 
f end of the summer, and 
retain their green colour 
until the next year, after 
which they become brown, 
[Hymenophyllum tinilaterale.] and finally almost black. 
This species is like its congener widely distributed 
throughout the United Kingdom, growing on the moun- 
tains and on damp rocks ; the present is, however, the 
more abundant of the two in the Highlands of Scotland 
nd in Ireland. It is found in other parts of Europe, at the 
Cape of Good Hope, in New Holland, and South America. 
The Hymenopkyllums may be cultivated in the same 
manner as the Trichomanet, The surface on which the 
plants are placed should be covered with a thin layer of 
sand and finely-cut sphagnum moss. 
