CRYPTOGAMIA Alga;.
G e n . C h a r . Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
S p e c . C h a r . Crust white, leprous, very thin. Shields
crowded, elevated, flat, olive-green; the margin
white, undulated.
W e received specimens of this Lichen (gathered in the
county of Durham) so long ago as January 1799, from the
Rev. Mr. Harriman and Mr. Oliver, and we are told of the
same having been found even before that time by Mr. Dickson.
We have hesitated to describe it, from a suspicion of its
being possibly a variety of L. cerinus, v. 9. t. 627: but it
deserves at any rate to be known; and Mr. Harriman, who
is not at all inclined to multiply the species of this tribe on
slight grounds, has no doubt of its being distinct. He
informs us that “ this is an alpine plant, and is found upon
“ limestone only, its immediate support being moss or earth,
“ or sometimes partly earth and partly limestone. The disk
“ of the shields is at first yellowish green, or rather perhaps
“ greenish yellow, and at length becomes bottle-green.
“ L. cerinus is by no means an alpine Lichen.”------The
crust appears also to differ, being whiter, more leprous, and
very thin. The granulations scattered over it Mr. Harriman
finds to be young or abortive shields. The perfect shields
are numerous and often much crowded, elevated, white externally,
with a white undulated border, much elevated,
crenate and leprous when young. The disk is flat; and the
tendency of that part to turn more green instead of yellow, as
it advances in age, seems a strong proof of the distinctness of
the species.