/ 6 z
CRYPTOGAMIA Algae. .
G en. Char. Male, scattered warts.
Female, smooth shields o r tubercles, in which the
seeds are imbedded.
S pec. Char. Crust leprous, powdery, silvery-white.
Shields pale grey, flat, with a tumid white margin.
Syn. Lichen argenus. Ach. Prod. 8.
L . farinosus. Hoffm. Em m . 8. t. 1 . f . 1 .
Lecidea argena. Ach. Meth. 74.
Verrucaria farinosa. Hoffm. Germ. t . 2 . 171.
FO U N D on the rugged barks of old trees by Mr. W. Borrer,
whose specimens accord exactly with the authentic one sent
by Professor Acharius. It is very remarkable that the latter
abounds with shields, overlooked by our learned friend who
sent it, and which prove the plant a Parmelia according to
his system, not a Lecidea as he made it on Hoffmann’s authority.
N o . English writer has hitherto noticed this species. Its
crust forms broadish, rugged, mealy patches, of a greyish or
silvery white, with an edge fibrous at first, then smooth,
even, and greenish or olive-coloured. Shields scattered, sessile
or somewhat immersed, small; their disk flat, pale grey
or lead-coloured; their border tumid, even or slightly rugged,
of the hue and substance of the crust.
7923
y.Aeey. AASàâ. Tubtish'd b y J a { denter by, LemA^n-.