cd. 3, p. 31.— C'o&ma tremelloides Hook. Fl. Soot. ii. p. 72 ; Sm.
Eng. El. V. p. 213 ; Tayl. in Mack. Fl. Hib. ii. p. 111. Lichen
tremelloides Linn. fil. Suppl. PI. (1781) p. 4 5 0 ; Eng. Bot. t. 1981.
Lichen cocMeatus, Dicks. Crypt, fasc. i. (1786) t. 2. f. 9 ; With. Arr.
cd. 3, iv. p. 74.— B r it. E x s .: Cromb. n. 1 1 0 ; Larb. Lioh. Hb.
n. 3.
Differs from L. lacerum in the larger smoothish thallus, leaden-coloured
wlien dry, in the more rounded lobes wdtli entire margins, and in the
elevated, larger apothecia. The cortical layer is formed of rather large
angular cells. Sparingly fertile in S.W. England and W. Ireland.
Hah. Among mosses on moist rocks in maritime and mountainous
districts.—Dwfr. General, and usiiallv plentiful in the Channel Islands,
S. and W. Britain, and E. and S.W. Ireland.—B. AI. : St. Peter's Valiev,
Island of Jersey. St. Lawrence, Isle of Wight ; near Bri.xliam, Saltasli,
llaberton, Conwortliy, Wembury, and Totness, S. Devon ; St. Issey and
near Penzance, Cornwall ; Tenby, Pembrokesliire ; Barmouth and Harlech
Castle, Alerionethshire; Garn, Denbighshire; Llanberis Pass, Carnarvonshire
; Island of Anglesea. Dumbarton Castle, Dumbartonshire ;
Appin and Island of AIull, Argylesliire. Dunkerron Alt., Blackwater,
and Killarney, co. Kerry ; Kylemore and Dougbbraugh Alts., co. Galway.
Form polyphyllum Nyl. ex Leight. Lich. Fl. ed. 3 (1879), p. 32.
—Thalline lobes smaller, more divided and complicated, naked or
isidiiferous.
The thallus of this polyphyllous form when densely covered w ith isidia,
as it usually is, is form pichneum (Ach. Syn. p. 343), Cromb Grevillea
XV. p. 13. Not seen fertile. ’
Hah. On damp rocks among mosses in maritime districts.—Di'sfi-. Local
and scarce in S. England, the S.W. liighlands of Scotland, and N.W.
Ireland.—B. AI. : Near Torquay, S. Devon. Island of AIull, Argyleshire.
Near Kylemore, Connemara, co. Galway.
Subgen. 3. STEPHANOPHOHUS Flot. Linnæa, 1843, p. 16.—
Thallus crowdedly plicatulate ; apotbecia with th e thalline receptacle
plicato-rugose.
16. L. ruginosum Nyl. ex Cromb. Grevillea, xv. (1886) p. 13.—
Thallus membranaceous, roundly lobed, plicate, longitudinally and
crowdedly rugose, brownish- or greenish-lead-colourod, brownish-
black-furfuraceous on th e upper surface ; lobes complicate, undulate,
th e margins entire or crenulate. Apothecia somewhat large, slightly
concave or plane, red or brownish-red, th e thalline margin thick,
rugoso-plicato or furfuraceo-granulate ; spores ellipsoid or attenuate
a t both apices, 3-5 -sep tate, and also sometimes longitudinal! y divided,
0 ,0 2 0 -3 7 mm. long, 0 ,0 1 0 -1 7 vam.Ûàek.— Collema ruginosum Duf!
in Sohær. Enum. (1850) p. 251. Leptogium chloromelum Mudd
(non Nyl.), Man. p. 4 8 ; Carroll, Jo u rn . Bot. 1867, p. 254 ; Cromb.
Lioh. B n t. p. 9 ; Leight. Lich. El. p. 32, ed. 3, p. 32.
This can scarcely, even in an infertile state, be mistaken for any otlser
Britisli plant. I t has sometimes been confounded with two exotic
snecies viz. X. Brehissonii Alont., and X. chloromelmn N y l.; but it is quite
distinct from both. According to Nyl. (m htt.), L. Brebusomi has the
thallus less plicatulo-con-ugate, and is moreover whitish- or ^ey isb -
downy benealh ; while X. chloromdum (an American species) has the
thallus and receptacle less corrugate, the latter being subsmootb. The
specimens found in this country are sterile.
Hah On the trunks of old trees and on rocks aniong mosses in maritime
and mountainous districts.—Distr. Sparmgly in IS. W ales and S.W .
Ireland - B . AI.; Garth, near Dolgelly and Barmouth, Alerionetbsbire.
Eagle's Nest and Dinish, Killarney, co. Kerry.
Siibgen 4. AIALLOTIUM Ach. Lich.Hniv. (1810) p. 644.—Thallus
membranaceo-lobed, cellulari-corticate above, tomentose beneath ;
gonimia moniliform. Apothecia lecanorine; spores subelhpsoid,
murali-divided.
17. L. s a tu rn i-
num Nyl. Syn. i.
(1858) p. 1 2 7 .—
Thallus large, sub-
monophyllous and
lobato-incised, or
polyphyllous and
sinuato-lobed, rounded
and entire a t
the margins, olive-
or leaden-brown,
Fig. 19.
above smooth or
slightly furfuraoe-
L ep to g ium s a h tm in um Nyl.—a . A’ertical section o f
a su p erficial p o rtio n o f th e tom en lo se th a llu s ,
ous, beneath greyish
x275. h. S te rigm a ta , a n d c, sp e rm a tia , X 275. ■
and densely tomen- , . i
lose. Apothecia moderate, plane, reddish-brown, thalline receptacle
cupular and somewhat prominent, margin thin, en tire; spores ellipsoid,
3-septate, becoming irregularly murali-multilocular, 0,020-
22 mm, long, 0,0 1 0 -1 1 mm. th ick .—Cromb. Liob. B n t. p. 9;
Leight. Lioh. El. p. 29, cd. 3, p. 8 ‘2.— Mallotium sa tu rnwum Gray,
N a ” Arr. i. p. 399 ; Mudd, Alan. p. 44. Collema saturninum Hook.
F l Soot ii. p. 71 ; Sm. Eng. El. v. p. 211. Lichen saturninus Dicks.
Crypt, fasc. ii. (1790) p. 21, t. 6. f. 8 ; AVith. Arr. ed. 3, iv. p. 6 0 ;
Eng. Bot. t. 1980.—Hrii. E x s .: Cromb. n. 5 ; Dicks. H o rt. Sio.
n. 24.
Though elsewhere a large plant, spreading extensively with iiim thallus,
with us it is smaller, thinner, and less polyphyllous. In damp shady
situations it often becomes blackish above when dry, contrasting with the
colour of the under surface. When smaller and furfuraceous it resembles
Collema flaccidum, from which it may always be recognized by the
minutely cellular cortical layer, and by the whitish down ol the under
surface. The apothecia are very rare in Britain.
Ilah. On the trunks of old trees, generally ash, by streams in upland
mountainous districts.—Di'sri-. Local and scarce in the b. and W . fJigli-