CRYPTOGAMIA Algos.
G e n . C h a r . Seeds in black, linear, sessile, simple or
branched, bordered clefts, in an uninterrupted crust.
S p e c . C h a r . Crust thick, chalky, very white. Clefts
prominent, aggregate, radiant, coal-black.
S y n . Opegrapha calcarea. Turn, MSS.
*
O n e of the most striking and distinct species of Opegrapha,
which we have long known on the mortar of old walls in
Norfolk and Suffolk, but which has been passed over as a variety
of some more common species growing on trees.
Mr. Turner has at length defined it, nor, since the genus has
been studied, can there be a doubt of its difference from all
hitherto-described species.
The crust is very conspicuous for its brilliant whiteness,
and unpolished chalky surface. The fructification is observed
by Mr. Turner to originate in little dots, each of which at
length becomes a more or less compound assemblage of radiating,
tumid, prominent clefts, no less remarkable for their
deep black hue than the crust is for its pure whiteness. Each
cleft has a strong longitudinal black furrow, with a thick,
rounded, simple border on each side.
17.90
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