LICHEN l'ucidus.
Lemon-coloured Rock Lichen.
CRYPTOGAMIA Algos.
Gen. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust thin, powdery, brittle, pale greenish
lemon-coloured. Shields small, sessile, convex, lemon
coloured, without a border.
Syn. Lichen lucidus. Ach. Prod. 39.
Lecidea lucida. Ach. Meth. 74.
T h e crust of this Lichen, in scattered powdery patches of a
bright light lemon-colour, without shields, attracted my attention
on the hard sand-stone rocks in the country about
Liverpool 2 years ago, especially at Woolton, Allerton, &c.
After long search I met with 2 or 3 shields on the walls of
Allerton hall, which determined its genus. Mr. W. Borrer
has lately observed the same at Cuckfield, Sussex, as well as
about Tunbridge wells, spreading over the perpendicular rocks,
and having the appearance of a Lepraria. That gentleman has
also found shields, and has communicated specimens to
Mr. Sowerby. Although not furnished with correspondent
ones from Dr. Acharius, I conceive there can be no doubt
respecting his synonym.
The crust is more or less scattered, indeterminate, generally
very thin, powdery, and easily rubbed off, of a beautiful pale
lemon-colour, sometimes inclining to light green, and very
obvious at a distance. It is less dense and continued, as well
as of a very different hue from L. orostheus, of which Dr. Acharius
at one time suspected this to be a variety; but he is now
satisfied of the contrary. When the crust bears fructification,
it is only on the older and more substantial parts. The shields
are sessile, rather convex, of a full lemon-colour, without a
border; when old, somewhat rugged or lobed.