O P E G R A PIIA astroidea.
Starry Opegrapha.
CRYPTOGAMIA Algce.
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 limited, irregular, very thin, membranous,
smooth,, greenish white, somewhat shining.
Clefts immersed, flattish, branching in a starry form.
S y n . Opegrapha astroidea. Ach. Meth. 25.
O. radiata. Pers. in Ust. Ann.fasc. 7. 2 9 .t. 2 . / . B, b.
Lichen astroices. Ach. Prod. 24.
V e r y common on the smooth barks of trees, and when
magnified a far from inelegant object.
The crust forms patches of various shapes, clearly limited,
but not marked with any black edge. It is at first thin even
and uninterrupted, generally white, or varying from a pale
to a deeper olive. By age it divides and cracks, sometimes
scaling off irr little flakes, assisted by the protruding fructification.
The latter consists of innumerable coal-black specks,
more or less regularly radiating like stars, sometimes only
three-cleft like a biro s claw. They are white internally, but
* very black in all their external surface as well as sides.
Professor Acharius has lately, we understand, constituted,
in Schrader s Journal, a new genus called Arthonia, into
which, whether it be a good genus or not, we presume to
think he has improperly admitted this species.
m ?
Febj, l8o <? Publiihed, lÿJa JJow erh yfo n d o n .