A distinct species with much of the general aspect of L. phceops,
but with different apothecia. I t also somewhat resembles states of
L. coarctata, but the different thalline reactions with CaCl and the
firmer immarginate apothecia keep it distinct. These latter, numerous
though scattered, are at length somewhat difform, and in more shady
situations they remain immersed.
Hal. Cn rocks, granitic and schistose, in maritime and mountainous
districts.—Distr. Cnly a few localities in W. England andW. Ireland,
but plentiful where it occurs.—B. M. Bolt Head and near Torquay,
Devon ; near Penzance, Cornwall ; Cader Idris and Barmouth,
Merioneth; Craigforda, Shropshire; Glena, Killarney, Dunkerron and
Blaokwater Bridge, Kerry; Lough Inagh and Doughruagh Mt.,
Connemara, Galway.
23. L. coarctata Nyl. in Act. Soc. Linn. Bord. ser. 3, i.
p. 358 (1856).—Thallus effuse, thinnish, rimulose, subareolate or
continuous, whitish or greyish (Kf+yellowish, CaCl+ deep-red).
Apothecia small, innate-sessile, plane or convex, brown, reddish-
brown or blackish, with a spurious white epithalline margin
which is sometimes connivent and almost closed over the
apothecium ; hypothecium almost colourless ; paraphyses slender,
dark a t the apices; spores ellipsoid, large, 0,014-24 mm. long,
0,007-12 mm. th ic k ; hymenial gelatine pale-bluish then wine-red
with iodine.—Cromb. in Grevillea xxii. p. 9 & Lich. Brit. p. 66 ;
Leight. Lich. FI. p. 2 7 8 ; ed. 3, p. 280. Lichen coarctatus Sm.
Fngl. Bot. t. 534 (1799). Pinodina coarctata S. F. Gray Nat.
Arr. i. p. 449 (1821). Lecanora coarctata Hook, in Sm. Fngl.
FI. V. p. 187 (1833); Tayl. in Mackay FI. Hib. ii. p. 134; Mudd
Man. p. 154.
Lxsicc. Leight. n. 177 ; Johns, n. 332.
Viewed by many authors as. a Lecanora from the spurious thalloid
margin of the apothecia, which, however, contains no algal cells.
Nylander has also referred it to th a t genus (Enum. Lioh. Eret. Behr.
p. 12), where its place would be in the Aspieilia section. I t is a very
protean species both as to the thallus and the apothecia, the differences
in which give rise to the varieties and forms th a t follow. In the
typical specimen figured in Engl. Bot. the thallus is thin, rimoso-
areolate, rugulose, in which state it seems to be Lecanora ocrinceta,
Ach. Lioh. Univ. p. 380 & Syn. p. 102. The apothecia are numerous,
usually more or less scattered, becoming in age convex, blackish, with
the spurious margin obliterated.
Hab. On walls and rooks, chiefly brick and sandstone, in maritime
and upland districts.—Distr. Only here and there in England and
W ales; not seen from Scotland or Ireland.—B. M. Yarmouth, Norfolk;
Hendon, Middlesex ; Reigate and Leith Hill, Surrey ; Fairlight,
Hastings, Sussex; St. Minver and near Cambourne, Cornwall; Cader
Idris, Merioneth.
Var. ^ elacista Cromb. Lich. Brit. p. 66 (1870).—Thallus
effuse, th in or very thin, subleprose or rimulose, contiguous or
somewhat scattered, whitish or greyish-white, often subobsolete.
Apothecia minute or subminute, concave or plain, the epithalline
margin pulverulent, a t length naked, evanescent; otherwise
nearly as in the type.—L. coarctata form elacista Leight. Lich.
FI. p. 278 pro p a rte ; ed. 3, p. 281 pro parte. Parmelia elacista
Ach. Meth. p. 159, t. iv. f. 4 (1803). Lecanora coarctata var. 8
elacista Mudd Man. p. 154 pro parte (1861).
Lxsicc. Mudd n. 124 ; Larb. Lioh. Hb. nos. 41, 342; Johns
n. 333.
Differs in the thinner, often subpulverulent thallus and the smaller
apothecia, which are often blackish and immarginate in age. In both
respects, however, it presents diversities resulting chiefly from the
nature of the habitat. Thus when pulverulent the thallus is frequently
little visible, when it is form cotaria Cromb. in Grevillea xxii. p. 9
[Lecidea cotaria Ach. Meth. Suppl. p. 11 (1803)). Ccoasionally it is
entirely absent, when it is form depauperata Leight. Lioh. El. ed. 3,
p. 282 (1879). The apothecia in a very young state are subglobose, with
the pseudo thalline margin connivent, and concealing the epithecium ;
it is then form variolosa Leight. Lich. El. ed. 3, p. 282 (Plot. Lich.
Siles. p. 120), having, as Acharius says [I. c.), the aspect of Verrucaria
leucocephala. Very rarely this margin is persistent and more or less
crenulate (form subcrenulata Cromb.).
Hab. Cn rocks, walls, and stones in maritime and mountainous
districts.— Not uncommon in most parts of Great Britain and
probably also of Ireland ; not found with certainty in the Channel
Islands.—B. M. Leith Hill, Surrey; Springfield near Chelmsford, and
Galleywood Common, Essex ; St. Leonards and Fairlight Glen, near
Hastings, Sussex; Luocomb and near Shanklin, Isle of Wight;
Launceston, Withiel and Newlyn Cliff, Cornwall; Axe Edge, Buxton,
Derbyshire; Ledbury, Herefordshire; Malvern, Worcestershire ; Dolgelly
and Cader Idris, Merioneth ; near Ayton, Cleveland, Yorkshire;
Eglestone, Durham ; Achosragan Hill, Appin, Argyll; Ben Lawers
and^ Craig Tulloch, Perth sh ire ; near Portlethen, Kincardineshire;
Craig Guie, Braemar, Aberdeenshire; Bantry and Kilcully, Cork;
Kylemore and Doughruagh Mt., Connemara, Galway.
Var. y glehulosa Cromb. Lich. Brit. p. 76 (1870) & in
Grevillea xxii. p. 9.—ThalJus determinate or subdeterminate,
thickish, verrucose-glebulose or subsquamulose, the squamules
tumid, somewhat scattered or crowded, minutely lobed a t the
circumference, whitish or glaucous-white. Apothecia small,
plane or slightly convex, reddish-brown, becoming dark-red, the
margin thin, speedily evanescent; otherwise as in the type.—
L. coarctata f. glebulosa, f. involuta and f. ornata Leight. Lich.
FI, p. 279 (1871); ed. 3, p. 281. Lichen glebulosus Sm. Fngl.
Bot. t. 1955 (1809). Lepidoma glebulosum S. F. Gray Nat. Arr. i.
p. 462 (1821). Lecanora coarctata var. /3 ornata Sommerf.
Suppl. Fi. Lapp. p. 92 (1826); Mudd Man. p. 154 pro parte.
L. coarctata var. /3 glebulosa Mudd and var. y involuta Mudd
Man. p. 154 (1861). L. involuta Tayl. in Mackay FI. Hib. ii. p. 134
(1836). Psora glebulosa Hook, in Sm. Fngl. FI. v. p. 193 (1833).
Lxsicc. Leight. n. 149; Mudd, n. 123; Larb. Lich. Hb.
n. 170 ; Johns, n. 334.
Perhaps a subspecies, looking when best developed as if it were
even a distinct species. I t is then well marked, as stated by Sommer