The English flora - SeaweedAfrica

Opegrapha.] LTCHENES. H3
with regard to its apothecia, what Collema is to the foliaceous
Lichens, as respects the thallus. All are found on the bark of
trees.
1. A. impolite, Borr. (pruinose Arthonia); crust somewhat
tartareous thin cracked uneven white, apothecia immersed
flat confluent brownish lead-coloured pruinose. Borr. in E. Bot.
,s,, rpf.f.2692.f. 1.
—
Arthonia pruinosa, Ach. Lich. Uhiv.p. 147.
t. \.f 3. it Syn. p. 7.—Lichen impolitus, Ehrh. Cr. {not E. Bot.
which is probably taken from a common appearance of Spiloma
gregarium,— S. twnidulvm, Ach.,— of which a more perfect state is
represented at t. '2151. Borr.)^~Verrucaria impolita, Hoffm—
Parmelia impo/ita, Ach. Meth.
Frequent on boarded buildings and on the rugged bark of old oaks.
2. A. lurida, Ach. (lurid Arthonia); crust obsolete continu-
ous smooth dull lead-coloured or brownish, apothecia sessile
roundish slightly convex reddish-black. Borr. in E. Bot.
Suppl. t. 2692. f. 2. Ach. Syn. p. 7— Spiloma paradoxum, Ach.
Syn. t. 3.
Probably not rare on bark, in shady places. On Holly and Oaks,
Sussex, Mr. Borrer. Fir-trees in Ireland, Sir Thomas Gage.— 1 he
crust of this is so thin, that Mr. Borrer questions whether it is anything
more in reality than a discolouration of the bark, and whether it has a
just claim to rank among the Lichens. The synonym of Achanus Mr.
Borrer has given upon the authority of original specimens in the Museum
of the Linnaean Society.
3. A. Swartzidna, Ach. (Swartzian Arthonia); crust thin
cartilagineo-membranaceous cracked cream-coloured, apothecia
roundish repand wavy and depressed uneven sometimes con-
fluent. Ach. in Schrad. N. Joum. v. 1. fasc. 3. p. 13. t.4.f. 1,
,i Syn. p. 5. E. Bot. t. 2079.
On the smooth bark of trees, Sussex. Mr. Borrer.—h is upon this
species that the genus Arthonia was founded byAeharius. Other Lichens,
which he lias referred to it, should be separated from it, in the opinion ot
other Botanists. I have followed Mr. Boner's suggestion in removing
Arthonia lyncea of Ach. to Opegrapha. The A. astroidea of Achanus,
Mr. Borrer thinks is too nearly allied to this; but the species so called
in A'. Bot. he suspects rather to belong to Opegrapha atra.
4. Oim'oi: \ imi a. . \eh. < tpegrapha.
Tludhis crustaceous, membranaceous or Leprose, spreading, adnate,
uniform. Apothecia dm lb, > elongated, simple or branch-
ed, sessile or immersed, the dish narrow with a proper border
and sometimes with an additional our derived from the thallus,
— Named from off* hollow, and '^/-'•- Writing: from il> curious
/,/,//„ resembling inscribed characters.—The character of this
genus depends upon the elongated apothecia or Ureiia*, with a
raised proper border ; and Mi-. Borrer, whose arrangement and
synonyms of the spe< :ies, obligingly communicated to me, I en-
tirely follow, includes aUothrc//w/>.W..v,,f Aohnrios;oensideving