m
Allied to subgenus Squamaria, undev udiieh the species have usually
been included, but distiuguislied by the cephalodia, which are constant in
all the species (most of which are exotic) under all conditions of growth.
8. L. g e lid a Aoh. Lioh. Univ.
(1 8 1 0 ) p. 428.—Thallus orbicular,
closely adnate, rimoso-areolate in
th e centre, laoiniato-radiose a t tho
circumference, sordid-white or pale-
greyish (K-f-yellow, CaCl + red) ;
cephalodia scattered, g re jish - or
brownish-flesh-coloured. Apothecia
moderate, adnato, eoncavo or
plane, pale-testaoeous, the thalline
margin thick, entire ; sporos ellipsoid,
0 ,0 1 4 -1 8 mm. loug, 0 ,0 0 6 -8
mm. thick.—Cromh. Journ. Linu.
Soo. Bot. XV. p. 232 ; Hook. Fl.
Scot. ii. p. 50 ; Taj'l. in Mack. F l.
Hib. ii. p. 140.— Squamaria gelida
Sm. Eug. El. V. p. 1 9 5 ; Mudd,
Man. p. 129 ; Cromh. Lich. Brit,
p. 45 ; Leight. Lich. Fl. p. 174, ed. 3,
p. 159. Placodium g d id um Gray,
Nat. Arr. i. p. 448. Lichen gelidus
Linn. Mant. ii. (1771) p. 1 3 3 ;
Dicks. Crypt, faso. ii. p. 19 ; With. Arr. iv. p. 26 ; Eng. Bot. t. 699.—
B r it. E.VS. : Dicks. Hort, Sio. n. 25 ; Larb. Lich. Hb. n. 60.
Easily recognized amongst Bi'itish Lecanorei by the cephalodiiferous
thallus, which is usually of moderate size, greyish-flesh-coloured when
moist, and occasionally sprinkled w ith greyish or greyish-olive, impressed
soredia. The ceplialodia, which are more or less numerous according to
the development of the thallus, are depresso-verrucarioid, at length radi-
ato-rimose, internally with the gonimia glomerulose, or often several moniliform.
The apothecia, when present (for the thallus is often sterile), are
usually sparingly scattered. A young sterile state, with the thallus little
developed and scattered and bearing a few young cephalodia, is form dispersa
(non Fr.), Cromh. Grevillea, i, p. 171 ; Leiglit. Lich. Fl. iii. p. 160.
Hah. On rocks, granitic, schistose, and old red sandstone, in upland and
suhalpine districts.—Dfsir. Rather local in England and Wales, more
frequent in Scotland, and probably also in Irelaud.—B. M. : St. Austell,
Cornwall ; Cader Idris, Dolgelly, and Llyn Bodlyn, Merionethshire ;
Eglestone and Teesdale, Durham; uear Kendal, Westmoreland; Knock
Morton Screes, Cumberland. Netv GaUoway, Kirkcudbrightshire ; Loch
Awe, Argyleshire; Craig Calliach, Ben Lawers, and Craig Tulloch,
Perthshire"; Clova and Oanlochan, Forfarshire ; Glen Caudlic and Glen
Cluny, Braemar, Aberdeenshire ; Rothiemurchus, Ben Nevis, and Fort
Augustus, Inverness-shire ; Hills of Applecross, Ross-sliire. Dunkerron,
and Connor Clifis, Dingle, co. Kerry ; Letterfrack aud Recess, Connemara,
CO. Galway ; Carntough, co. Antrim.
Fig. 60.
Lecanora {Placopsis') gelida Aeh. —a.
A gonimic gloiiierule and goniuvio
granules, X 350. h. Two spores,
X 500. c. Sterigmata and spermatia,
X 600.
L E C A N O -L E C ID E E I. 357
Subgen. 4. PLACODIUM Nyl. Not. SaUsk. pro F. et Fl. F.
F o rh . V. (1866) p. 126.—Thallus radiating, usually effigurate a t the
circumference. Apotheoia often a t length subbiatorine ; spores 8næ,
ellipsoid, polari-bilooular, usually with longitudinal tube, very
rarely simple or subsimple ; hymenial gelatine (especially the
theoæ) bluish w ith iodine. Spermogones w ith shortly jointed
sterigmata, and straight, oblong or baoilliform spermatia.—Placodium
DC. Fl. F r. ii. (1805) p. 377 ; Nyl. Mém. Soo. Chorb. iii.
p. 177.
p r
0 ( .
o .
' • ' F U 0 ‘ 0 n G ' -O o I
'jîo ! ¡0*0 ; ; Û0 J “ Û ! “ J
" ! 0 0 0 ; Oq ■ ■ OûûU)3o^ùo a
Fig. 01.
Lecanora [Placodium) callopiama Ach.—a. Vertical section of thallus, X 200.
b. Three spores, X 500. o. Sterigmata and spermatia, X 500.
Known by the more or less radiose thallus (which is variously yellow,
very rarely whitish), by the usual mode of division of the spores, and by
the short arthrosterigmata. The spermogones are externally somewhat
prominent, with the ostioles iu the yellow thalli orange-yellow.
9. L. fulgens Ach. Lioh. Univ. (1810) p. 437 ; Nyl. ex Hue,
Revue Bot. 1886, p. 21 .—Thallus orbicular, submonophyllous,
adnate, opaque, laciniato-divided a t th e circumference, pale yellow
or citrine ; lacmiæ crenate or crenato-lobulate (K - f reddish-purplish).
Apotheoia small, plane or convex, orange-coloured, K - f purplish, the
thalline margin concolorous, a t length obliterated ; spores simple,
0 ,0 0 9 -1 2 mm. long, 0 ,0 0 5 -6 mm. thick.— Placodium fulgens Gray,
Nat. Arr. i. p. 447 ; Mudd, Man. p. 131 ; Cromb. Lioh. Brit. p. 45 ;
Leight. Lioh. Fl. p. 178, ed. 3, p. 164. Squamaria fulgens Sm. Eng.
El. v. p. 195. Lichen fulgens 8w. N. Act. Upsal. iv. (1794) p. 246 ;
Eng. Bot. t. 1667 ; Dicks. Crypt, faso. iv. p. 24.—B rit. Exs. : Larb.
Cæsar. n. 27 ; Lich. Hb. ii. 296 ; Cromb. n. 155.
From the simple spores tliis might he referred, as has often been done,
to subgonus Squamaria. Its true place, however, is shown hy the