L I C H E N atratus,
Inhj-crusted Lichen.
CRYPTOGAMIA Algoe.
G e n . C h a r . M a le , scattered warts.
F em a le , sm o o th shields or tubercles, in w h ich the
seeds are imbedded.
Spec. Char. Crust c o n tin u ed , ev en , m in u te ly tessella
ted , o f a g r ey ish rather op a q u e black; ; its fragments
an gu la r , s lig h tly co n ca v e . Shields in the
in te r stic e s, h a lf sunk, flattish, c o a l-b la ck , w ith an
e lev a ted , entire, b la ck border.
F o u n d by Mr. G. Don, upon granite rocks at the head of
Loch Lee in Glen Esk, Angtisshire, but rarely. Having in
vain attempted to refer this Lichen to any of those described
by Acharius, though furnished with most of his specimens,
and being anxious to clear up, as much as possible, the difficulties
of the tribe to which it belongs, some of which may be
found in v. 26, t. 1829—31, and another in v. 25, t. 1737,
we hope a figure and description of it may not be unwelcome.
It most resembles, at first sight, the true Lecidea fusco-atra,
Ach. Meth. 44, for which that author doubtingly quotes Lichen
carbonarius of Wulfen, more agreeing, as we judge, with
his Lecidea fumosa, 41; but the crust of this fusco-atra consists
of minute, concave, shining-black, crowded warts, on a
deep-black ground, agreeing rather in structure with our
t. 2317 and 2336.
Our L . atratus has a genuine tartareous, minutely tessellated,
though thin, crust, composing inky stains, as it were, on the
hard rock, and in that respect looking like L . niger, t. 1161.
The surface of the fragments is very smooth, of a greyish black,
with little or no gloss. Shields numerous, sunk in the cracks,
scarcely raised above the surface, rather smaller than the fragments,
very black, slightly concave, with an elevated, thick,
entire, smooth border, of their own colour and substance.—
L. atratus of Hedwig is a fungus.