The English flora - SeaweedAfrica

226 LICHENES. [Usnea.
greenish inflexed smooth border. Sm.—Ach. Syn. p. 298.
Lichen pollinarius, Ach. Prodr.— E. Bot. t. 1607. Dijl Muse.
t.2l.f. 57.
On old trees, posts and rails, rarely on rocks, in England. Particularly
abundant in Norfolk and Suffolk, on old barn-doors, which are sometimes
covered with the plant.
b. Thattus subcylindrical, filamentous^ nearly pendent.
a. Thallus with a central thread. Apothecia scutelliform, without
a border; ciliated (orbillai).
FAM. XIV. UsNEiE.
31. Usnea. Ach. Usnea.
Thallus subcrustaceous, rounded, branched, generally pendu-
lous, with a central thread. Apothecia (orbiflce,) orbicular, ter-
minal, peltate, entirely formed of the substance of the thallus
and nearly of the same colour, the circumference mostly without
a border and (generally) ciliated.—Name ; from dchneh or
dchnen, in Arabic (Axneeh or Usnee, according to Dillenius,)
the name of some Tree-Lichen.
1. U. fiorida, Ach. (fioivery Usnea); thallus nearly erect
rough greenish-grey branched, the main branches bearing innumerable
small horizontal nearly simple fibrous ones, apothecia
plane large pale flesh-coloured bordered with long radiating
fibres or cilia.
—
Ach. Syn. p. 304.
—
—
—
Lichen Jloridus, Linn.—
E. Bot. t. 872.—Dill. Muse. t. 13. /. 13.
Branches of old trees, frequent in hilly and mountainous countries.
2. U. pliedta, Ach. (stringy Usnea); thallus pendulous smooth
pale, branches lax much divided subfibrillose the ultimate ones
capillaceous, apothecia plane broad
and very long. Ach. Syn. p. 305.
ciliated, the cilia slender
Lichen plicatus, Linn.—
E. Bot. t. 257.—Dill. Muse. t. 11. /. 1 (3. hirta; nearly erect
greyish-green much branched scabrous bearing flesh-coloured
solid warts, branches very much divided flexuose intricate sub-
fibrillose
—
Ach. Syn. p. 305.
—
Lichen hirtus, Linn.—E. Bot.
t. 1354.—L. Jloridus, /§. Buds.—Dill. Muse. t. 13./. 12.
Common on old trees and park-pales, both «. and /•.— The Lichen
hirtus of Linnaeus and E. Bot., Acharius has referred to the Usnea plicata;
but to me it appears to have a nearer affinity with U.florida, and
the distinctions between that and the present species are very unsatisfactory
and I fear not much to be depended upon. Indeed the Lichen
plicatus of E. Bot. looks more like the U. barbata ; and Sir J. E.
Smith observes that the main-stems often crack here and there, as is the
case with that species : and then I do not see how they are to be distinguished.
3. U. barbata, Ach. (jointed Usnea); thallus pendulous