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L I C H E N impolitus.
Unjiolijhed Lichen.
CRYPTOGAM1A Alga.
Gen. Char. Male, fcattered warts.
Female, fmooth fhields or tubercles, in, which the
feeds are imbedded.
Spec. Char. Cruft white, powdery and cracked.
Tubercles numerous, deprefled, oblong, irregular,
obtufe, yellowifh-brown, clothed with deciduous
mealinefs, without any border.
Syn. Lichen impolitus. Achar. Prod. 56.
Yerrucaria impolita. Hoffm. FI. Germ. v . 1 . 1 7 a.
C jA T H E R E D , for the' firft time in Britain, by Mr. D.
Turner, on the trunks of trees at Bowton near Barton, Norfolk.
A fpecimen fent by Dr. Schrader proves this to be the
L . impolitus of the German botanifts, and therefore it ought
to be what Dr. Acharius has fo denominated ; but his de-
fcription of the fhields as “ margined and at length black,”
induces a fufpicion of his having confounded with this our
L . lynceus, t. 809, a very diftinct fpecies.
L . impolitus has a very white thin infeparable cruft, mealy
and cracked, not fmooth. Innumerable tubercles are regularly
difperfed over it, which when young are funk rather below the
furface, and feemingly bordered by the cruft, but have no real
border of their own. Their form is oblong, obtufe, curved,
fometimes very fhort and roundifh; in advanced age they project:.
They are of a yellowifh brown or dull orange hue; hut
that colour is remarkably concealed by a white mealinefs
which renders them fcarcely diftinguiftiable from the cruft,
but which is eafily rubbed off, and then the tubercles are very
evident.