( 16 BRITISH FERNS. 17
BRITISH FERNS.
I 'I
of the lobe, it is difficult to obtain a satisfactory view of these
pafts, and still more difficult to represent them by a figure. In
the annexed cut the lobe is supposed to he flattened : on the left
the unshaded portion represents the superior
indusium thrown back ; the inferior indusium
is entirely removed, and the attachments of the
® thecæ are indicated along the margin of the
^ shaded part ; on tlie right the unshaded part
represents both the indusia throvm back, together
with the thecæ contained between them,
the thecæ occasionally protruding beyond the
indusia.
Wlien the pinnula is barren, there is no trace of an indusium :
the disposition of the lateral veins is very nearly as in the fertile
pinnulæ, but they very obviously cease at the margin, which is
without a channel or vein of any kind.
This is not only the most abundant but the most useful of
our ferns : in Scotland, particularly in the Western Highlands,
I observed it used for thatching cottages; in many parts of
England it serves as packing for fruit and fish, and in Wales
it is harvested as litter for horses. In wandering among the
mountains of Wales I have constantly met with sleighs drawn
by a ragged pony, and laden with Pteris by some industrious
W elshwoman.
ROCK BRAKES.
A l l o s o r u s C r i s p u s .—Bernhardi, Sprengel, Sadler, Presl.
Osmunda Crisp«.—Linneus, Hudson, Lightfoot, Bolton, Berkenhout.
Onoclea Crispa.—Roth.
Phoroholus Crispus.—Desveux.
Cryptogramma Crispa.—Brown, Hooker, Mackay, Francis.
Pteris Crisp«.—Smith, Withering.
Stegania Onocleoides.—Gray.
LOCALITIES.
England . . . Abundant on the mountains and about the lakes of Cumberland and Westmoreland ;
more sparingly on the mountains of Yorkshire and Lancashire.
W a l e s ..............A b u n d a n t on th e m o u n ta in s o f C ae rn a rv o n sh ire ; ™ ™
Piinljmmon ; on walis near Llyn Tregarien, Dolgelly, Tan-y-Bwlch, Aherglas y ,
Beddgelert, and Lianberris.
SCOTLAND . . . Mountains of Aberdeenshire. Argyleshire, Perthshire, &e. but not abundantly.
IKELAND . . . . Mourne Mountains, county Down ; Liberties of Carriekfergus, county Antrim,
F o r separating this species generically from the three following,
I am unable to assign any better reason than that every
author has considered it distinct; it has by three eminent
botanists been made the type of a new genus ; viz. by Bernhardi,
under the name AUosorus ; by Desveux, under the name
Phoroholus; and by Brown, under the name Cryptogramma.
The name I have adopted has the claim of priorRy. The only
characters distinguishing this plant from our British Polypodia
are, that the fronds are both fertile and barren, and that the
margin of the fertile pinnula is reflexed, covering the masses of
thecæ. In a few species, nearly allied to A. crispus, the masses
of thecæ are linear.
The root is fibrous, the fibres very numerous and tough, and
tenaciously adhering to the earth or stones ; the rhizoma is dark
brown, and extends itself horizontally, but very slowly ; and the
plant, without a careful examination, appears to he tufted.
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