ra th e r narrow, imbricate. Ajjotliecia small, tho thalline margin
entire, or a t length subcreuate ; spores ellipsoid or oblongo-ellipsoid,
often somewhat curved, 2-locular (with K polari-bilooular), 0 ,0 1 0 -1 6
mm. long, 0 ,0 0 4 -8 mm. thick.—Martind. N a tu ralist, 1887, p. 359.
— Physcia decipiens Arn. Flora, 1866, p. 529, 1875, p. 153, t. v.
figs. 2, 3.—Placodium decipiens Leight. Lioh. F l. p. 176, cd. 3,
p. 102, refers chiefly to th e following subspecies.
Characterized hy the central thalline verrucas, the narrower radii, aud
more especially by the spores, the true structure of wliich, however, as
in many other instances, becomes apparent ou tlie application of K. The
typical condition here described, represented by Arnold’s Lich. Exs.
n. 445, may, as suggested by Nylander (Flora, 1883, I. o.), be the original
Lichen murorum of Iloffmanu. In the very few British specimens seen,
tlie apothecia are few and not well developed. The spermogones, however,
are more frequent with spermatia ohlongo-bacilliform, 0,0.30-35
mra. long, 0,0007-9 mm. thick. I t is, as noted by Martindale, I. c., a
somewhat variable plant, and the specimens (well fertile) issued by
Ijarbalestier (s. n. var. camboricmn Larb.) are referable to a state in
which the thallus becomes effuse, or nearly so, the peripheral lobes being
very irregularly produced.
Ilab. On walls in lowland districts.—Disfr. Local in S., W., and E.
England.—li. M .: Shoreham, K e n t; near Cirencester, Gloucestershire ;
MUton Church, Canihridgeshire.
Subsp. 2. L. tegularis Nyl. Flora, 1883, p. 106.—Thallus somew
h a t small, short, plioato-radiate a t the circumference, diffracto-
areolate iu th e centre, naked or suffused, vitelline, pale-yellow, or
miniate. Apothecia small, concave, th en plane, concolorous or sub-
eonoolorous with th e thallus, th e thalline margin entire ; spores as in
the typo, or oocasionally somewhat smaller (0 ,0 09-0,011 mm. long,
0 ,0 0 3 5 -4 5 mm. thick).— Cromh. Grevillea, xviii. p. 44.—Lichen
tegularis Eh rh . Exs. n. 304 (1785). To miniate states are referable
pro pa rte Squamaria miniata 8m. Eng. FL ii. p. 195. Placodium
murorum y. minicUum Mudd, Man. p. 1 3 2 ; Cromb. Lioh. Brit,
p. 45 ; Leiglit. Lich. F l. p. 175, cd, 3, p. 162 (u t sp. propr.).
Lichen elegans Eng. Bot. t. 2181 (two left-hand figs.).—B r it. E x s .:
Leight. n. 207 ; Mudd, n. 95 ; Larb. Lich. Hb. ii. 51.
A smaller and rather variable plant, distinguished from the type and
the preceding subspecies, with both of which it is subconfluent', by the
characters given. The thallus is at times somewhat scattered with the peripheral
radii little distinct. I t is always well fertile, the apothecia being
numerous and varying in colour like the thallus. The spermogones have
the spermatia either as iu the type or a little smaller (0,002-3 mm. long,
0,0007-8 mm. thick). I t is to vermilion-coloured states that the trivial
name miniata (lloffm.) has more especially been applied ; bnt as other
species growing in dry and exposed habitats, especially calcareous, have
similarly coloured thalli, the name cannot with propriety be used either
in a specific or varietal sense.
Hab. On rocks and walls, very rarely on old timber, from maritime to
upland situations.—Histr. Here and there throughout Great B rita in ;
rare iu the Chaunel Islauds; not seen from Irelaud.—B. M .: Kozel,
Island of Jersey. Near Glynde, Sussex; Kemble, Gloucestersliire ;
Weston, Oxfordshire ; Llanymynech Ilill, Shropshire ; Ayton, Cleveland,
Yorkshire; Broiigliton Castle," Westmoreland. The Trossacbs, Pertli-
shire ; Cove, Kincardineshire ; near Aberdeen.
Form Arnold! Nyl. Flora, 1883, p. 106.—Thallus very small,
epruinose, ciniiabarine, shortly and narrowly radiose, diffracto-
areolate ill th e centre. Apothecia minute, concolorous witlt th e
th allu s.—Cromb. Grevillea, xviii. p. 44.— Lecanora Arnoleli Wedd.
Bull. Soo. Bot. xxiii. (1876) p. 96. L. miniata Tayl. in Mack. F l.
Hib. ii. p. 140.
Only a minute condition of the type with naked miniate thallus and
apothecia. The tliree British speciineus seen are well fertile.
Hab. On dry calcareous rocks in maritime and mountainous districts.
—Histr. Only in N.E. England, the N. Grampians, Scotland, and S.W.
Ireland.—B. M. : Hartlepool, Durham. Morrone, Aberdeenshire. Dunkerron,
CO. Kerry.
Yar. ft. obliterascens Nyl. Flora, 1883, p. 99.—Thallus small,
slightly and narrowly radiate a t the circumference, vitelline. Apothecia
small, plane or convex, th e thalline margin a t length often
obliterated ; spores 0 ,0 08-0,011 mm. long, 0 ,0 0 4 -5 mm. thiok.—
Cromb. Jo u rn . Bot. 1885, p. 195.
According to Nylander I. c., apparently only a variety of this subspecies.
In our British specimens, it occurs on the substratum in small
scattered patches, which occasional^ have a tendency to become confluent.
The apothecia are numerous and crowded, almost obliterating
the thallus.
Hah. On schistose rocks and walls in maritime and upland di.stricts.
—Histr. Found only in N. England, the Central Grampians, and N.E.
Scotland.—B. M. ; Near Ayton, Cleveland, Y’orkshire ; Bassenthwaite,
Cumberland. Craig Tulloch, Blair Athole, Perthshire; Cove, Kincardineshire.
12. L. dissidens Nyl. Flora, 1875, p. 298.—Thallus orbicular,
appressed, somewhat smaU, stellato-radiate, vitelline ; lacmiæ
narrow, plane or somewhat convex, discrete, subfree a t th e circumference
(K - f purplish). Apothecia small, plane, concolorous (K - f
purplish), th e thallino margin suhentire or crenulate ; spores
0 ,0 0 9 -0 ,0 1 6 mm. long, 0 ,0 0 5 -7 mm. th ic k .—Cromb. Grovillea, iv.
p. 1 8 0 .—Placodium murorum form dissidens Leight. Lich. Fl. ed. 3,
p. 161. Lichen flavicans W ith . Arr. ed. 3, iv. p. 25 pro p a rte .—
Lichen elegans Eng. Bot. t. 2181 (right-hand fig.).
Looks like a variety of L. eleyans, but is distinguished by the colour
(rarely suhminiate) of the planer laciniæ. I t approaches states of
subsp. L. tegularis, but the laciniæ are more discrete, and the thalline
margin of the apothecia usually more or less crenate. The British
specimens are well fertile.
Hah. On slate roofs of outhouses and on brick walls in lowland and upland
tracts —Distr. Found only liere aud there in England, but probably
y