ry 6 [ 949 ]
LICHEN ater.
Black-Jhielded Lichen.
CRYPTOGAMIA Alga.
G en . C har. Male, fcattered warts. Female, fmooth
fhields or tubercles, in which the feeds are imbedded.
S pec. Char. Cruft rugged, granulated, white.
Shields flattifh, coal-black, with an elevated,
white, at length zigzag and notched, border.
Syn. Lichen ater. Hudf. 530. Lightf 813. With.
d. 4* 18. Hull. 289. Relh. 426. Sibth. 323..
Abbot. 261.
L. tephromelas. Achar. Prod. 67.
Lichenoides cruftaceum et leprofum, fcutellis nigri-
cantibus majoribus et minoribus. Dill. Mufc. 133.
TJ - H IS Lichen is very common on walls, and even on
rocks. It feems to flourifh moft abundantly on brick buildings
in rather expofed lituations.
The cruft fpreads circularly, and is moderately thick, granulated
and rugged, fometimes very white, but often a little
brownith or greyifb, not at all mealy. When dry it is very
friable. The fhields are extremely numerous, and often
crowded together, feffile, various in fize. Their difk nearly
flat, or rather concave than convex, of a perfect char-coal
black in every ftage of their growth, by which it is diftinguifhed
from all varieties of L. fubfufcus, a fpecies we fhall take a
future opportunity of illuftrating. The margin of the fhields
is confpicuous by its elevation and whitenefs, generally fpeaking,
for in fome inftances it is found tinged with lead-colour, and
then the plant becomes L. cinerafcens of Withering, but has
nothing to do with t. 4. f . 3 . of Hoffmann’s Enumeratio. By
age this margin grows zigzag and varioufly notched.
Dillenius thought our fcrupofus, v. 4. t. 366, a variety of this. JTov. /. 1607. Hh&Wh/ed' ty Sowcrty, S o nde ns