J S' s [ 2156 ]
LICHEN Glaucoma,
Wall-eyed Lichen.
CRYPTOGAMIA Algae.
GfiN. Char, Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
S pec. Ch ar. Crust tartareous, cracked, uneven, hard,
greyish-white. Shields depressed, crowded; at length
tumid, deformed, black, brown or buff, with a strong
glaucous tinge, and a wavy border from the crust.
Syn. Lichen Glaucoma. Ach. Prod. 56.
L. rupicola. Linn. Mant. 132? Huds. 525. With.v. 4.
13? Lightf . 806. Dicks. H. Sicc. fasc. 15. 2 2 .
L. varians. Davies Tr. o f L. Soc. v. 2 . 284. t. 28.
ƒ. 3. With.v. 4. 18.
L. compositus. With. v. 4. 13. t. 31. f . 2 , bad.
Patellaria Glaucoma. Hojfm. PI. Lich. v. 3. 9.
t. 52, 53.
Parmelia Glaucoma. Ach. Meth. 160. Winch v. 2 . 50.
F r e q u e n t on whin-stone, or slate, in mountainous countries.
The very hard, continued, distinctly bordered crust
follows all the inequalities of the stone, and is itself uneven,
cracked, tartareous, of a dirty greyish white externally; pure
white within. The shields are extremely remarkable, and account
for all the different descriptions and paradoxical relations
to be found under the above references. When young
they are level with the crust, scarcely bordered; when older
tumid, unequal, crowded, with a border from the substance
of the crust more or less elevated. The disk is either blackish,
lead-coloured, of a horny brown, or a brightish buff, in different
shields or parts of shields, but always, unless rubbed,
clothed with a fine glaucous powder or efflorescence. In some
cases it appears compound or proliferous. Our synonyms,
except where a mark of doubt is subjoined, are founded on
original specimens. L. rupicola of Linnaeus cannot be ascertained
; we therefore prefer the excellent name of Acharius.
We cannot assent to the opinion of some of our learned
friends that L. sulphureus, t. 1186, or crenulatus, t. 930, or
Swartzii of Acharius, are not perfectly distinct from this,
nor do we found our opinion on trivial observation.