The English flora - SeaweedAfrica

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}66 LICHENES. [Spiluma.
frequently almost covering the thallus. Sporules so minute that the
highest powers of the microscope are insufficient to discover their figure
those of the surface, which are deep brown with a fuliginous tinge,
rub off with the slightest touch and discover the dull but full yellow (or
orange-) colour of those which compose the internal part of the apothecium."—
In E. Bot., S. auratum is described and figured with a crust,
not belonging to it ; for it often spreads over the thick tartareous thalli
of Verrucaria and Opegrapha, &c.
6. S. nigrum. Turn, and Borr. (black Spiloma); crust inclining
to tartareous thin white with a narrow black edge, apothecia
roundish nearly flat at length confluent black. Turn, and
Borr. Lick. Br. p. 35. cc. variolosum ; crust powdery pure
white, apothecia convex but little confluent black. Coniocarpum
nigrum, Be Cand. Fl. Fr. ed. 2. v. 2. p. 324. Bubis and Be
Cand. Bot. Gall. v. 2. p. 695 Spiloma variolosum, E. Bot.
t. 2077.— S. melaleucum, Ach. Syn. p. 2.—(3. versicolor; crust
inclining to powdery grey variegated with greenish-yellow,
apothecia flat very confluent. *S y
. versicolor, Ach. in Web. et
Mohr Arch. p. 108. E. Bot. t. 2076.
—
y. erubescens; crust tartareous
reddish cracked into areolae, apothecia small shapeless
for the most part distinct.
Not unfrequent on old trees, chiefly Oaks; sometimes on bare wood
in sheltered places. Old Church-walls in Suffolk. Sir T. Gage, Bart.—
/3. On smooth bark, as on Hornbeam, in Norfolk and Suffolk, and on
Walnut at Albourne, Sussex. y. on smooth trees in Norfolk and Suffolk,
and at Henfield and Albourne, Sussex.
7. S. fuliginosiun, Turn, and Borr. {sooty-fruited Spiloma);
crust inclining to tartareous but still very thin nearly white with
a fuliginous edge composed of downy fibres, apothecia very
minute punctiform * confluent sooty-black. Turn, and Borr.
Lick. Br. p. 37.— S. microclonium, E. Bot. t. 2150, {not Ach.).
On the rugged trunks of old trees. In Windsor forest, Mr. Sowerby.
Near Esher, Surrey ; Belton and Blundeston, Suffolk.— Allied to S.
nigrum, from which it is distinguished by the colour, size and indistinct
figure of its innumerable apothecia, which are so uninterruptedly scattered
over the thallus as to render the plant liable to be mistaken for a
Lepraria.
8. S. decolorans, Turn, and Borr. (staining . Spiloma); crust
spreading widely very thin and for the most part filmy, apothecia
flat inconspicuous confluent of a purplish- grey. Turn, and
Borr. Lich. Br. p. 39. E. Bot t. 2399.
Common on old walls, boarded buildings and pales.—This is, in habit,
allied to some Variolarice; but as the fructifications appear to be pulvi-
—
nuli rather than soredia, the plant is arranged here.
9. S. punctatum, Turn, and Borr. (dotted Spiloma); crust
filmy somewhat powdery thin white, apothecia scattered minute
punctiform solid, sporules blackish-brown superficial.
Turn, and Borr. Lich. Br. p. 40. E. Bot. t. 2472.
On old oaks at Coltishall, Norfolk.— Of doubtful genus, in some respects
allied to Arthonia, in others to S. gregarium.
;