The species are more or less social, occurring in wooded regions, chiefly
in old woods (tliongh sometimes saxicole and lignicole), where, with their
pale-greenish or yellowish thalli often very considerably elongate, they
form, especially when fertile, a fine ornament to the trunks and branches
of the trees, covering them as if with a “ shaggy fleece.” The limits of
many species have been little understood by recent authors, the earlier
writers having in this respect a more accurate judgment. Accordingly,
modern lichenologists, following Fries, have usually included several distinct
species as varieties under TJsnea barhata Fr., supposing th a t they
were connected by intermediate states. Nylander lias, however, again
separated these, and pointed out th at there are sufilcient external and
anatomical differences to entitle them to rank as distinct species—oue of
the more important characters being the size of the spores. Nearly all
the species are often sorediiferous, especially iu barren specimens ; while
on the thalli of several “ cephalodia ” are not imfrequent. These are
lateral, pale, or at lengtli brown, tuberculoso-pulvinate, solid, internally
dense (with no distinct gonimic layer), aud composed of thin, interwoven
filamentose elements {vide Nyl. Syn. i. p. 266). The spermogones are
rare aud covered by the tliallus, on which they appear as slight protuberances,
with spermatia 0,009 mm. long, about 0,001 mm. thick. In the
British species the cortical layer usually gives a more or less yellowish
reaction with K, but is uiitinged by OaOl. Frequently, however, the
positive reaction is very faint or even wanting in portions of tbe same
specimen, so that it cannot be employed for the discrimination of species,
as Dr. Stirton lias done (Scottish Naturalist, vi. p. 101 et seq.).
1. U. flo rid a Aeh. Meth. (1803) p. 307 pro p a rte .—Thallus erect,
rounded, scabrous, very muoh branched, pale-greyish or groyish-
green ; branches p a ten t, nearly simple, w ith crowded horizontal
fibrils. Apothecia plane, moderate or large, pale or somewhat glaucous,
oiliate a t th e margins, th e cilia long, fibrillose, rad ia tin g ;
spores shortly ellipsoid, 0-007-11 mm. long, 0 ,0 0 6 -7 mm. thick.—
Gray, Nat. Arr. i. p. 403 ; Hook. Fl. Soot. ii. p. 70 : Sm. Eng. Fl.
V. p. 226 ; Cromb. Jo u ru . Linn. Soo. Bot. xvii. p. 5S5. Usnea barhata
a. flo r id a Mudd, Man. p. 69, t. i. f. 1 5 ; Cromb. Lioh. Brit,
p. 2 3 ; Leight. Lioh. F l. p. 83, ed. 3, p. 75 ; Tayl. in Mack. PI. Hib.
ii. p. 86. Lichen flo r id u s Limi. Sp. PL (1753) p. 1 1 5 4 ; Huds. FL
Angl. p. 463 ; AVith. Arr. ed. 3, iv. p. 50 ; Eng. Bot. t. 872.
Usnea vulgatissima tenuior et hrevior, cum orbimlis Dill. Muse. 69,
t. 13. f. 13. Lichenoides quod Miiscus arhoreus cum orbiculis Dill,
iu E a y Syn. od. 3, p. 65, n. 6.—B rit. Exs. : Cromh. n. 16.
Easily recognized by its constantly erect babit, and the horizontal
fibrils with which the branches are covered. The tliallus is usually rigid
and more or less scabrid. AA’hen several plants grow in proximity they
form, with their large and numerous apot lecia, a striking object on the
forest trees, and present the appearance of a_ small parasitic shrub. The
apothecia are terminal and smooth, though in age they become rugulose
and shortly fibrillose on tbe underside.
Hab. On the branches of trees, rarely erratic on rocks, in upland
woods aud forests.—Histr. General and not uncommon in Great Britain,
but more frequent and fruiting more freely in the Southern tracts ; rare
in tbe Cbanuel Islands ; uot seen from Ireland, tbougb said by Dr.' Taylor
{I. c.) to be common.—B. AI.; Island of Guernsey. Near Lydd, K e n t;
New Forest, Hants ; Lydford and near Totnes, Devonshire ; Bocconoc
and near Penzance, Cornwall; Hay Coppice and Whitfield, Herefordsbire;
near Porthogo, Breconshire ; Dynevor Castle, Carmarthensliire; Hafod,
Cardiganshire; Island of Anglesea; Gibside AVoods, Durham; Ambleside,
AVestmoreland. New Galloway, Kirkcudbrightsbire; Pentland Hills,
near Edinburgh; near Inverary, Argyleshire; Stronaclacban Woods,
Killin, Perthshire; Durris AVoods, Kincardineshire; Countes,swells AVoods,
near Aberdeen, and Ballochbuie Forest, Braemar ; Lochaber, Inverness-
shire.
2. IJ. h i r t a Hoffm. Deutsch. FL ii. (1795) p. 133.—Thallus somew
h a t small, nearly erect, cæspitoso, crowdedly branched, densely
and minutely fibrillose, greenish- or yellowish-whito; branches often
covered with verrucoso-pulverulent soredia. Apotheoia small, pale,
the margin with short radiating fibrils ; spores shortly ellipsoid,
0 ,0 0 6 -8 mm. long, 0 ,0 0 4 -6 mm. thick.—Cromb. Linn. Soo. Journ.
Bot. xvii. p. 555.— Usnea harhata ¡3. hirta Mudd, Alan. p. 6 9 ;
Cromh. Lich. Brit. p. 23 ; Leight. Lich. Fl. p. 84, ed. 3, p. 76.
Usnea plieata y. hirta Gray, Nat. Arr. i. p. 404 ; Hook. Fl. Soot,
ii. p. 70 ; Sm. Eng. Fl. v. p. 226 ; Tayl. in Mack. Fl. Hib. ii. p. 86.
Lichen hirtus Linu. Sp. PI. (1753) p. i l 5 5 ; Huds. FL Angl. p. 462 ;
Lightf. Fl. Soot. ii. p. 895 ; With. Arr. ed. 3, iv. p. 46. Usnea vulgatissima
tenuior et hrevior, sine orhicuUs Dill. AIuso. 67, t. 13. f. 12.
— B rit. Exs. : Leight. n. 1 pro parto ; Aludd, n. 35.
Distinguished from the preceding, which it resembles in habit, by
being much smaller (usually about 1-2 inches iu height), more cæspitose,
branched aud fibrillose. Occasionally it is very small and pulvinate, and
is sometimes only sparingly sorediiferous. The apothecia are very rare
iu Great Britain, and are found only on tbe smaller conditions. Aliuute
cephalodia, however, are not unfrequeut on the main branches.
Hab. On old pales (oak and larch), aud occasionally on the branches of
trees iu wooded tracts.—Distr. General in maritime and upland districts,
sometimes abundant, especially in the Central Highlands of Scotland ;
apparently rare in Ireland and in the Channel Islands.—B. AI. ; Island of
G uernsey. AA’altliamstow, Essex ; Lydd, Kent ; near Lewes, Sussex ;
near Hyde, Isle of W ight ; Lyndhurst, New Forest, Ilampsbire ; Coryton,
S. Devon ; near Penzance, Cornwall ; Cirencester, Gloucestershire ; Gopsall,
Leicestershire ; Kowter Ilocks, Derbyshire ; near Oswestry and
Hauglimond Ilill, Shropshire; Conway Falls, Carnarvonshire ; Bettws-
y-Coed, Denbighshire; Island of Anglesea ; Ingleby, Cleveland, Yorkshire
; near Ilexham, Northumberland ; Ashgill, Cumberland. New
Galloway, Kirkcudbrightshire; near Aloffat, Dumfriesshire; Pentland
Hills, near Edinburgh ; Inverary aud Appin, Argyleshire; Killin, Perthshire;
Much ills, Kincardineshire; Park, near Aberdeen; Alar Forest,
Braemar, Aberdeenshire ; Rotlnemurchus AA’ood, Inverness-sbire ; Lairg,
Sutherlandshire. Near Belfast, co. Antrim.
3. U. d a sypoga Nyl. ex Stiz. St. Gall. Nat. Ges. (1876) p. 202.—
Thallus elongate, pendulous, scabrous, sparingly branched, greyish-
white or pale-grej’ish ; the branohos long, divergent, simplish, with
short, p a tent, crowded fibrillæ. Aqothocia small or nearly mode