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A S P I D I U M fontanum.
Smooth Rock Shield-fern.
CRYPTOGAMIA Fil'uxs.
G en. Char. Fructifications scattered, in roundish
dots, not marginal. Jnvolucrum umbilicated,
bursting almost all round.
Spec. Char. Frond linear-lancêolate, smooth, mostly
bipinnate ; leaflets alternate, rounded ; their segments
very sharply toothed. Stalks winged. In-
volucrum oblong.
S yn. Aspidium fontanum. Sw. Fit. 57.
Polypodium fontanum. Linn. Sp. PL 1550. Sm.
FI. Brit. 1114. Huds. 456. With. 111. Hull.
238. Hillars Dauph. v. 3. 849.
P. n. 1706. Hall. IfisL v. 3. 15.
Adiantum filicinum durius crispum minimum. Barrel.
Ic. t. 4,32. f . 1 .
W E have at length ascertained this fern to our satisfaction,
and hasten to correct the errors respecting it in FI. Brit, into
which we were led by Linnaeus having confounded with it a
specimen that we now believe to be our Polypodium hyper-
loreum, t. 2 0 2 3 . The above synonyms are certainly correct,
as, we trust, is the following information.
Mr. Hudson gathered this plant above Wybourn in Westmoreland,
and received it from Agmondesham, or Amersham,
church, Bucks. We have a specimen gathered by the late
Mr. Alton in the spot last mentioned, though the plant is said
to be found there no longer; but this ascertains the species.
The- character -and description of Linnaeus agree with it,
though not wdth the mistaken specimen above mentioned,
whose capsules are intermixed with hairs, and whicn we had
in view while writing FI. Brit. The tufted root bears many
fronds, from 2 to 6 inches high, rigid, smooth, of a somewhat
glaucous green, linear-lanceolate, composed of numerous,
alternate, pinnate or pinnatifid leaflets, whose lobes are
very sharply toothed and slightly spinous, and all the stalks
are winged. Dots at the midrib of each lobe, round, which
makes the plant an Aspidium, though the singularly white
involucrum is lateral and oblong, approaching to the nature
of a Darea. There seems moreover some general affinity
between the present fern and Asplenium lanceolatum, t. 2 4 0 .
One of our specimens was communicated by. Mr. Dickson.
We have seen no living ones.