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16
4. UMBILICAEIA
IIo ffm.ri.L io h .(1 7 9 5 )
p. 109 pro parte ; Nyl.
Flora, 1875, p. 303.
—TTuillus efribrillose
beneath. Apothecia
lecanoroid, with th a llino
receptacle, contain
in g no gonidia ;
hypothecium brownish
hlack; spores solitary,
2uæ or 8næ,
brown or colourless,
murali-looular or simple
; hymenial gelatin
e bluish and then
wine-red with iodine.
Spermogones somew
h a t prominent; spermatia
short, cylindrical.
Formerly distinguished
from the following
genus by different authors
on insufficient
grounds, this has been
definitely aenmteiy sseeppaarraatieedu buyy F i g . 5 3 .
N v l a u d e r o n a c c o u n t o f xjmhiUcaria pmtnlata H o ffm .—n. Vertical section of
t h e p e c u lia r ty p e o f t h e th a llu s , x 2 0 0 . h. V e rtic a l sectio n o f ap o th e c ium ,
a p o th e c ia . t le s e a r e x 3 0 . c. A t h e c a a n d p a ra p h y s is , x 3 5U . ¿ .T w o
iu a c e r t a in w a y k c a - sp o res, x 5 fO . c. V e rtic a l s e c tin oi th a llu s w ith a
n o r in e , b u t n o t t r u l y s o ; sp erm o g o n e , x 3 0 . / . S te rigm a ta a n d s p e rm a tia ,
fo r th o u g h th e y p r e s e n t x 5 0 0 .
externallva thalline re- a i
ceptacle Composed of the cortical and medullary layers, they do not contain
gonidia [vide Nyl. Flora, I. c.). As to the structure ot the thMlus
will be seen from tig. 5 3 « th at this consists of four layers. These
are—( 1 ) aii epithalline layer more or less developed or evanescent
fwlience the presence or absence of pruina on the upper surface); (2) a
corticali-gonidial layer, tbe gonidia occupying the lower half of the more
darkly delineated portion ; ( 3 ) a white medullary lay e r; and (4 ) il '‘O)'-
tical ‘layer on the under surface, of which the upper portion is « h ^droid
(sometimes partly wanting) and the lower (blackish) cellular (c /i._INyl.
Flora I c ) The spermogones have the spermatia in all the species ot
nearh' the same size, viz. 0 ,0 0 4 mm. long, 0 ,0 0 1 mm. thick.
The genus is divided into two suhgenera, founded upon difierences m
the cortical texture.
Subgen. 1. LASALLIA Aldrat (Fl. Pa r. (1836) p. 202 pro parte).
Thallus papulose above, lacunoso-foveolate beneath, in ternally
with th e chondrohvph® wanting in th e lower concave portion of
th e pustules. Apo'tliecia with the spores solitary or 2nffi, murali-
divided, brown.
1. U. pustulata Hoffm. Deutsoh. Fl. ii. (1795) p. 11 1 .—Thallus
large, monophyUous, inoiso-lobed a t tho oiroumferenoe, papulose,
pale-greyish or groyish-brown, subpruinose, sprinkled with large
fuliginoso-fioGOOse glomeruli ; beneath deeply lacunoso-foveolate,
naked, brownish or greyish-pruinoso, very minutely rimuloso-areo-
late ( K / , Apothecia moderate, superficial, scattered,
somewhat plane ; spores largo, solitary, 0 ,0 2 8 -7 0 mm. long, 0 ,0 1 8 -
34 mm. thiok.—Sm. Eng. El. v. p. 219 ; Mudd, Man. p. 115, t. ii.
f. 35 ; Leight. Ann. Mag. Nat. Hist. ser. 2, xviii. p. 294 ; Cromb.
Jo u rn . Linn. Soe. Bot. xvii. p. 570.— Gyrophora p u stu la ta Gray,
Nat. A rr. i. p. 478 ; Hook. Fl. Soot. ii. p. 42 ; Turn. & Borr. Irieh.
Br. p. 232 ; Tayl. in Mack. El. Hib. ii. p. 155 ; Cromb. Lioh. Brit,
p. 40 ; Leight. Lich. FL p. 154, ed. 3, p. 143. Lichen gmstalatus
Linn. Sp. PL (1753) p. 1 1 5 0 ; Huds. Fl. Angl. p. 4 5 4 ; Lightf. El.
Scot. Ü. p. 858 ; With. Arr. ed. 3, iv. p. 64 ; Eug. Bot. t. 1285.
Lichenoides pustulosum cinereum et veluti amhustum Dill. Muso. 226,
t. 30. f. 1 3 1 .—B rit. Exs.-. Leight. n. 1 6 6 ; Larb. Cæsar. n. 2 5 ;
Cromb. n. 52 ; Bohl. n. 125.
The peculiar pustular and isidio-glomerulose upper, and the deeply
pitted under surface of the thallus at once distinguish this from the other
British species of the tribe. The thallus, which is greenish when moist,
is normally orbicular, becoming at length irregular in shape, and often
attains a very large size. The apothecia, which are rare in Britain, are
scattered among the glomeruli chiefly towards the circumference, and
are at first concave, then plane or convex, with the margin at. length
excluded.
Hah. On rocks aud boulders, rarely on old walls, in moimtainous di.stricts.—
Distr. Somewhat local, though plentiful where it occurs in the
Channel Islands, S. and W. England, S. Scotland, the W. Highlands
and Shetland, Scotland, and in S.W. Ireland.—B. AI. ; La Aloye, Island
of Jersey ; Island of Guernsey. Blackstone Rock, near Bovey Tracey,
Ilay Tor and Hunter Tor, Dartmoor, Devonshire ; Helminton, Cornwall ;
Alalvern Hills, Worcestershire ; Charnwood Forest, Leicestershire; Oaer
Caradoc, Shropshire ; Cwm Bychan, Alerionethshire ; Capel Curig and
Nant Gwynant, Carnarvonshire; Nepha, Westmoreland; Wastdale,
Cumberland. New Galloway, Kirkcudbrightshire ; Loch Sligachan and
Loch Corruisk, Isle of Skye ; Ben Nevis, Inverness-shire ; Sandy Loch,
near Iierwick, Shetland. ‘Alizen Head and Glengariff, co. Cork; near
Dunkerron, co. Kerry.
Subgen. 2. AGYROPHORA Nyl. Elora, 1878, p. 247.—Thallus
epapulose above, efoveolato beneath, inte rn ally with the chondro-
hyphæ continuous in th e cortical layer of th e lower surface. Apothecia
with th e spores 8næ, simple, colourless.
2. U. atropruinosa Sohær. Ser. Mus. Helv. vi. (1829) p. 109,
t. 12-14.—Thallus moderate, monophyUous or subpolyphyUous,
rigid, th in ly areolato-rimulose or rugoso-areolate, brownish-black,
greyish-pruinose in the centre ; beneath smoothish or very finely
granulato-areolate, black or p a rtly paler, often pruinose (medulla
K - ,C a C l—). Apothecia somewhat prominent, nearly moderate,
Y 2
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