t 2409 ]
LEPRARIA nigra
Black Lepraria.
■ ■ — aBw—' —
CRYPTOGAMIA Alga.
Gen. Char. Seeds in a powdery substance, loosely
clothing a membranous or fibrous crust.
Spec. Char. Crust filmy, greyish. Fructification
black, extremely minute, in a thin, even, pow-
dery layer.
S y N . Lepraria nigra. Turn. 8$ Borr. Lich. Brit. zj. 1. 21.
A b o u t this there can be no uncertainty. It is only remarkable
that so common a production should not before have had
its nature investigated or defined. The squared tops of oaken
gate-posts, in particular, are generally black, as if sooty or
inky, with this Lepraria. Mr. Borrer has observed it to have
a grey filmy basis or crust, which is to be detected in its earliest
stage only, but serves to prove its nature. Fructification
in extremely minute round black grains, which stain the finger,
though less readily than some of the Spilomata, and cover
the whole surface of the crust in a thin continuous layer.
We readily asseijt to the supposition of the writers of the Li-
chenographia Britctnnica, that many botanists may have taken
this for Byssus antiquitatis, because we have, for our part,
Without much consideration, supposed it such; really not
knowing, any more than our fellow labourers in this mine of
obscurity, what that Byssus properly is. In several such cases
the ideas of the first writers on these plants ha,ve been too vague
to allow us to determine what they meant, without the assistance
of a specimen.