carea Miidd, Man. p. 101, t. 3. f. 55. Urceolaria calcarea Sm. E ng.
El. V. p. 172 ; Tayl. in Mack. Fl. Hib. ii. p. 132 ; Gray, Nat. Arr.
1. p. 459. Lichen calcareus Linn. Sp. PI. (1753) p. 1 1 4 0 ; Huds.
F l. Angl. p. 442 ; W ith . Arr. ed. 3, iv. p. 6 pro minima parte.
Lichen tessellatus Eng. Bot. t. 553. Urceolaria. tessellata Ach., Gray,
N a t. Arr. i. p. 4 G 0 .-B r it. E.vs.: Leight. n. 1 3 ; Mudd, n. 1 3 3 :
Larb. Lioh. Hb. n. 1G6.
Easily recognized, among British species by the whitish or chalky-
wliite thallus. In its more tvpical condition it is a. concreta (Schaer
bpicil. p 73) Leight. Lich. Fl. ed. 3, p. 193 (tessellata, Aeh.), with the
tliallus determinate, often subeffigurate a t the circumference, and the
areolæ contiguous, angulose. The apothecia are numerous, often crowded,
at times naked, with the proper margin at length discrete from the
tlialhne margin. The spermogones are frequeut, dark-brown or blackish
with spermatia aciculari-cyliudrical, 0,007-9 mm. long, about 0,001 mm’
thick. '
Hab. On calcareous rocks and walls, rarely granitic, in maritime and
upland districts.—Distr. General and common in limestone tracts of
Great Britain and Ireland ; not seen from the Channel Islands.—B. AI. :
Burgh Castle, Suffolk ; Peasemarsh, Sussex ; Plymouth, S. Devon ; near
I enzance, Cornwall; Bathampton Downs, Somerset; Cunning Dale,
near Burton, Derbyshire; Alalvern Hills, Worcestershire; Barmouth,
Mermnethshire ; Great Orme’s Head, Carnarvon; Island of Anglesea
Bilsdale, i orkshire ; Eglestone and Teesdale, Durham ; Levens, AVest-
morelaud. Appm and Island of Lismore, Argvleshire; Craig Tulloch,
Blair Athole, Perthshire ; Morrone, Braemar, Aberdeenshire. Dunkerron
CO. Kerry ; Alaam, Connemara, CO. Galway. *
Var. /I. contorta Nyl. Flora, 1872, p. 554.—Thallus effuse,
white or greyish-white, th e areolæ more or less discrete, elevated
m th e centre, depressed and a t times subeffigurate at' the circumference.
Apothecia immersed.—Leight. Lich. Fl. ed. 3, p. 193.—
A spicilia calcarea ¡3. contorta Mudd, Man. p. 162. Urceolaria
contorta Tayl. in Mack. F l. Hih. ii. p. 132. Uchen contortus Hoffm
Deutsoh. Fl. ii. (1 7 9 5 ) p. 186.—Hrii. E.vs. : Leight. n. 322.
Distinguished by the form of the discrete or subdiscrete thalline
areolæ. I t usually spreads extensively over the substratum and is well
lertile.
On calcareous rocks in maritime, but chiefly upland districts.—
Distr. Somewhat local in Great Britain and Ireland.—B. AI • Near
Kingskerswell, S. Devon ; Symmond’s Yat, Herefordshire ; Ashwood Dale
Derbyshire ; near Oswestry, Shropshire ; Great Orme’s Head, Carnarvon-’
J i r e ; Ieesdale Durham. The Ochils, near Stirling; Craig Tulloch,
Blair Athole, Perthshire; Craig Guie, Braemar, Aberdeenshire. Thé
O Donognues Prison, Killarney, co. Kerry.
Form monstrosa Cromh. Grevillea, xix. (1891) p. 67.—Thallus
effuse, snow-white ; areolæ discrete, scattered, rounded, convex,
entire a t th e margins. Apothecia abortive, minute, deeply im^
mersed.—i . calcarea var. monstrosa Lamy, Bull. Soc. Bot. t. x x x .
(1883) p . 392.
Only a well-marked form of this variety, characterized by the isolated
areolæ, in each of which tliere is a central umbilicus indicating the
abortive apothecia. Probably it may be only a very young condition.
Ilab. On calcareous stones of a wall io an uplaud situation.-Dish-.
Only very sparingly among the Central Grampians, Scotland.—B. AI. :
tilen Fender, Blair Athole, Perthshire.
^ Var. y. Hoffmanni Somm. Suppl. F l. Lapp. (1826) p. 102.—
Thallus thinnish or thiok, contiguous or subcontiguous, glaucescent.
Apothecia elevated, moderate or somewhat large, th e margin often
rugoso-crenate ; spores 0 ,0 2 1 -3 4 mm. long, 0 ,0 1 6 -1 8 mm. thick.—
Cromb. Grevillea, xix . p. 57 ; Lich. Brit. p. 54 pro p a rte ; forma
Hoffmanni Leight. Lioh. F l. p. 209 pro parte, ed. 3, p. 193.
Urceolaria Hoffmanni Gray, Nat. A rr. i. p. 459 pro parte. Lichen
Hoffmanni Aoh. Prodr. (1798) p. 31 ; E ngl. Bot. t. 1940.—jSrfi.
E xs. : Mudd, n. 134.
A very distinct variety, if not a subspecies, having much the general
aspect of I . gibbosa, but belonging to I . calcarea, as shown by the
spermatia, which in form and size are identical. From var. /3, with
which it has often been confused, it differs in the more contiguous and
differently coloured (at times subphimbeous) thallus and the leas immersed
apothecia.
D a i. On rocks and walls (not exclusively calcareous) in maritime, but
chieffy in hilly districts.—Distr. Only here and there in Great Britain ;
apparently rare in N.AA'. Ireland.—'B. AI. ; Beachy Head, Sussex ; near
Cirencester, Gloucestershire ; Buxton, Derbyshire; Chance’s Pitch, Alalvern,
Worcestershire; near Roseberry, Cleveland, Yorkshire; Levens,
Westmoreland. Ben Cruachan, Argyleshire ; Glen Fender, Blair Athole,
I erthshire ; Portlethen, Kincardineshire. Doughruagh mts., Connemara,
CO. Galway. o o > j
173. L. verrucosa Nyl. Mém. Soc. Cherb. t. v. (1857) p. 1 1 3 ;
Lioh. Scand. p. 156.— Thallus effuse, verrucoso-unequal, naked or
slightly pulverulent, white or glaucous-white (K - , Ca Cl—). Apothecia
immersed in th e verruoæ, moderate, concave, a t length
somewhat plane, blackish, naked or pruinose, tb e th allin e margin
thick, entire^ inflexed ; spores subollipsoid, large, 0 ,0 3 0 -6 2 mm.
long, 0 ,0 1 6 -3 2 mm. th ic k ; paraphyses not d isc re te ; hymenial
gelatine pale-bluish, then sordid-yellow or wine-red w ith iodine.—
Cromb. Lioh. Brit. p. 55 ; Leight. Lich. F l. p. 214, ed. 3, p. 200.—
Aspicilia verrucosa Mudd, Man. p. 164. Urceolaria verrucosa Ach.
Lioh. Univ. (1810) p. 339—B rit. Exs. : Cromb. n. 73.
Characterized by the white, usually more or less farinose thallus, hy its
place^ of growth, and by the large spores. The thallus varies somewhat
in thickness and colour according to the habitat, while on more sterile
soil it is smaller and determinate. The apothecia are numerous, at first
urceolate, then plane,_ the thalline margin rarely obsolete, when the
proper margin, which is thin and blackish, becomes conspicuous.
Hab. Incrusting mosses on rocks, rarely on the ground (chiefi}' calcareous),
in upland and subalpine situations.—Dfsfr. Local in N. England