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L I C H E N erythrellus-.
Orange Stone Lichen.
CRYPTOGAMIA Algce.
G en. Ch ar. Male, scattered wafts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
S pec. Char. Crust lemon-coloured, thin, dispersed,
in minute, angular, smooth fragments. Shields
sessile, deep orange, with a lighter border; at
length becoming nearly globose, and the border
obliterated.
Syn. Lichen erythrellus. Ach. Prod. 43.
Parmelia erythrella. Ach. Meth. 174.
D e t e c t e d by Mr. Hooker and Mr. Borrer on walls in-
Glen Orchy about Loch Tay, and elsewhere in the Highlands
last summer. Their specimens, drawn in our plate, agree
precisely with the authentic one sent by Dr. Acharius.
This is a minute species, but very distinct. Its original
describer suggests its affinity to L. salicinus, i. 1305, but
they surely cannot be confounded. The crust of this before
us consists of very minute, dispersed, angular, smooth,
lemon-coloured fragments, inseparable from the hard stone
on which it grows, and quite unlike in nature from the continued,
somewhat orbicular, crust of t. 1305. The diminutive
shields, larger however than the portions of the crust, are
scattered, sessile, of a deep reddish orange, with a thick,
smooth, paler border. In process of time the disk is said by
Dr. Acharius to become so convex that the border disappears.
We have not seen the shields in this state.