i 8 l [ 2317 ]
LICHEN verruculosus.
White-warted Black Lichen.
CRYPTOGAMIA Algae.
Gen. Char. M a le , scattered warts.
F em a le , sm o o th sh ie ld s or tu b e r c le s, in w h ic h the
seeds are im bedded.
Spec. Char. Crust in d e te rm in a te , very th in , fibrous,
b la ck , w ith w h ite , c o n v e x , c row d ed , smooth
warts. S h ie ld s so lita ry in e a ch wart, depressed,
c o a l-b la c k , w ith a border o f the same co lou r .
S E N T from the western part of the county of Durham, b j
Mr. Winch, who on comparing it with the authentic L. atro-
albus from Dr. Swartz, judged them to be the same, an opinion
which we, at first, did not hesitate to adopt. But on a more
critical examination of various fine specimens from Dr. Swartz,
as well as from Dr. Acharius himself, we have come to a contrary
conclusion. Their plant, well figured, though without
shields, by Wulfen, in Jacq. Coll. v. 2. t. 14. f. 1 , (not f. 4,)
bears on its black crust copious roughish grey or brownish warts,
and the shields are, as Acharius justly describes them, intermixed
therewith. Ours nearly indeed agrees with that in its
crust, which forms small indeterminate patches on the uneven
surfaces of the hardest rocks, and is extremely thin, black,
fibrous about the edges, inseparable from the stone; but its
warts are cream-coloured, smooth, less prominent or convex,
each bearing one, rarely more than one, central, small, very
black, depressed, flatfish, shield, whose slightly elevated border
is of the colour and substance of the disk. This difference
in the origin and situation of the shields is certainly essential.
I j. verruculosus isallied to those in v. 26.1. 1829—31. We find
nothing in Acharius to which it can be referred, except possibly
his Lecidea atro-virens fl, gerontica, which we have never
seen; but the characters accord imperfectly, and we are-very
sure our plant can have nothing to do with atro-virens.