simple, short, with straight spermatia 0,005-6 mm. long, scarcely
0,001 mm. thick. Several varieties and forms have been enumerated
by authors.
Hah. On peaty ground, not unfrequently on stumps of dead firs,
rarely incrusting mosses, from upland to alpine situations.—Distr.
General and common in Great Britain, no doubt also in Ireland, very
abundant on the Grampians ; not seen from the Channel Islands.—
B. M. Epping Forest, Essex ; Ightham, Kent ; New Forest, Hants ;
Dartmoor, Devon; North Wootton Common, Norfolk; near Buxton,
Derbyshire ; Lickey Hills, Worcestershire ; Cader Idris, Merioneth ;
Stiperstones Hill, Shropshire ; Guisboro’ Moor and Ayton Moor,
Cleveland, Yorkshire ; Eglestone, Durham ; near Hexham, Northumberland
; Pentland Hills, near Edinburgh ; Achosragan Hill, Appin,
Argyll ; Cookhill, Callander, Craig Calliach, Ben Lawers and Eannoch,
Perthshire ; Clova, Forfarshire ; Countesswells Wood, near Aberdeen ;
Glen Dee and Ben-naboord, Braemar, Aberdeenshire; Glen Nevis,
Invernessshire ; Lairg, Sutherland ; The Storr, Island of Skye ; Apple-
cross, Rossshire ; near Belfast, Antrim; Doveraile Mts., Cork;
Killarney, Kerry ; Delphi, Connemara, Galway.
Form 1. saxatilis Larb. in Leight. Lich. Flora, ed. 3, p. 259
(1879) (nomen).—Thallus very thin, the granules scattered,
subevanescent. Apothecia subminute, livid-brown ; otherwise as
in the type.
Exsicc. Larb. Lioh. Hb. n. 101.
Evidently only a depauperate state of the type, resulting from the
nature of the substratum on which it is erratic. In the specimen seen
the apothecia are either solitary or here and there confluent.
Hab. On moist rocks in an upland district.—B. M. By Lough Muck,
Connemara, Galway (the only locality).
Form 2. viridula Cromb.—Thallus granulose-leprose, greyish-
green, the granules a t length deliquescent, pulverulent, yellowish.
Apothecia somewhat small, blackish, solitary or confluent ;
otherwise as in the type.—L. decolorans var. y viridula Mudd
Man. p. 197 (1861); form aporética (vix Koerb. non Ach.)
Leight. Lich. PI. ed. 3, p. 259 (1879).
Exsicc. Mudd n. 166.
Differs merely in the colour of the more leprose thallus, which is
dark-green when moist. I t is apparently only one of the numerous
conditions of this polymorphous plant,' affected by atmospheric
influences.
Hab. On peaty ground in an upland tract.-—B. M. Cliffrigg, Cleveland,
Yorkshire (the only locality).
Var. /S escharoides Schær. Enum. p. 137 (1850).-—Thallus
granulose-verrucose, greyish-white. Apothecia convex, subim-
marginate, more or less confluent, brownish-black or black.—
L. decolorans var. /3 escharoides Mudd Man. p. 197 ; form
escharoides Leight. Lich. PI. ed. 3, p. 258. Lichen escharoides
Ehrh. Crypt. Fxs. n. 313 (1793). Lecidea decolorans var.
desertorum (Ach. ?) Cromb. in Grevillea xxii. p. 9 (1893).
Differs in the thicker more developed thallus and the constantly
darker apothecia, which are usually several confluent and irregular.
Hab. On peaty soil in mountainous regions.—Distr. Seen only
from N. England and the Grampians, Scotland.—B. M. Ayton Moor,
Cleveland, Yorkshire ; Eglestone, Durham ; Ben Lawers and Rannoch
Moor, Perthshire; Ben Avon and Cairngorm, Braemar, Aberdeenshire.
28. L. flexuosa Nyl. in Mem. Soc. Cherb. v. p. 121 (1857).—
Thallus effuse, thin, granulose, greenish or greyish-green (Kf +
yellow, CaCl + reddish), a t times subevanescent. Apothecia
small, sessile, plane, black or blackish, whitish within, the
margin thin, paler, often flexuose; hypothecium colourless ; paraphyses
brownish a t the apices ; spores ellipsoid, minute, 0,007—9
mm. long, 0,0035-45 mm. th ick ; hymenial gelatine pale-bluish
then tawny-reddish with iodine.—Mudd Man. p. 196; Leight.
Lich. PI. p. 2 6 0 ; ed. 3, p. 256. L. decolorans subsp. flexuosa
Cromb. Lich. Brit. p. 66 (1870). Biatora flexuosa F r. in Vet.
Ak. Handl. 1822, p. 268 (nomen) & Sched. Crit. viii. p. 11 (1826).
Exsicc. Cromb. n. 80; Larb. Lich. Hb. n. 341.
Very much resembles some lignicolous states of the preceding, of
which it may be only a subspecies. I t differs, however, in the constantly
darker apothecia and more especially in the much smaller
spores. The British specimens seen are well fertile.
Hah. On old pales and stumps of trees, chiefly larch, in upland
wooded districts.—Distr. Rather local, though plentiful where it
occurs, in Great Britain; not seen from Ireland.—B.M. Near Ulla-
combe, Bovey Tracey, Devon ; Bardon Hill, Leicestershire; Haughmond
Hill, Shropshire ; Lounsdale, Cleveland, Yorkshire; Teesdale,
Durham; Glen Falloch, Craig Calliaoh, and Achmore, Killin, Pe rth shire;
Countesswells Woods, near Aberdeen.
Form aeruginosa Leight. Lich. FI. p. 260 (1871); ed. 3,
p. 256.—Thallus leprose-pulverulent, dark verdigris-green; otherwise
as in the type.—Lecidea aeruginosa Borr. in Engl. Bot.
Suppl. t. 2682 (1831); Hook, in Sm. Engl. FI. v. p. 181.
L. flexuosa var. ¡3 aeruginosa Mudd Man. p. 197 (1861).
Exsicc. Leight. n. 4 0 6 ; Larb. Lich. Hb. nos. 65, 66.
Differs merely in the thalline granules becoming dissolved into an
ieruginose powder. I t often occurs sterile and might then be taken
for a Lepraria.
Hab. On old pales and on the bark of old trees in upland wooded
situations.—Distr. Not uncommon throughout England; rare in S.
Irelan d ; not seen from Scotland.—B. M. Highbeeoh, Epping Forest,
and Chelmsford, E ssex; near Mill Hill, Middlesex ; Leith Hill, Surrey;
Cuckfield and Henfield, Sussex; Lyndhurst, New Forest, H a n ts ;
Ullacombe, near Bovey Tracey, Devon; near Virginia Water, Berks ;
Brabaham Park, Cambridgeshire; North Wootton, Norfolk; Goyt
Bridge, near Buxton, Derbyshire ; Twycross, Leicestershire ; Batten-
liall, Worcestershire ; Morda, Oswestry, Shropshire; Baysdale, Cleveland,
Yorkshire; Glenmire, Cork.