Keswick, Cumberland. Acliosragan Hill, Appin, Argyleshire ; Craig
Tulloch, Blair Athole, Perthshire ; Glen Callater, Braemar, Aberdeenshire.
Kylemore Lake, Connemara, co. Galway.
18. P. melaleuca Dub. Bot. Gall. t. ii. (1830) p. 673.—Thallus
subeffuse, thin, smoothish, rimuloso-verruoose, yellowish-creara-
coloured (K + yellowish, K(CaCl)+ orange-red). Apotheoia in con-
vexo-depressed, irreg u lar verruoæ, lacerate a t th e margins, the
ostioles depressed, brownish-hlack, a t length pseudo-disciform ;
spores 2næ, 0,072—75 mm. long, 0,023—25 mm. th ick .—Mudd, Man.
p. 2 7 5 ; Leight. Lioh.Kl. p. 240, ed. 3, p. 230 ; Brit. Angio. Lioh.
p. 29, t. 10. f. 3.— Thelotrema melaleumm Turn. & Borr. Lioh. Br.
p. 183 ; Sm. Eng. El. v. p. 161. Lichen melaleucus Eng. Bot. xxxv.
(1813) t. 2461.
The fertile verrucæ are for the most part scattered, at times 2-8 confluent,
very rarely crowded, with the ostioles 1 or more, and the margins
lacerate, inflexed and irregular. They thus appear lecanoroid, and give
tlie plant somewhat the aspect of young states of F. Wulfenii. From
this, however, it is definitely separated by the number of the spores.
Hah. Ou smooth trunks of trees in upland wooded situations.—Histr.
Found only in a few localities in S. and Central ' England and in N.
Wales.—B. M. : Shiere, Surrey; St. Leonard’s Eorest, Sussex; New
Forest, H an ts; Twycross, Leicestershire; near Barmouth, Merionethshire.
19. P. pustulata Nyl. Act. Soo. Linn. Bord. sér. 3, t. i. (1856)
p. 441.—Thallus subeffuse, th in n ish , subrimose, greyish-white
(H —, CaCl—). Apotheoia several, in small, convex verruoæ; th e
ostioles punctiform, confluent, blaclrish; spores 2næ, 0,0 7 0 -0 ,1 2 0
mm. long, 0 ,0 3 4 -4 4 mm. thiok.— Cromb. Grevillea, xix . p. 59 ;
Leight. Angio. Lich. p. 30, t. 10. f. 4 ? ; Lich. El. p. 244, ed. 3,
p. 234 pro p a rte ; Mudd, Man. p. 275 pro p a rte ; Cromb. Lich.
Brit. p. 60 pro pa rte .—Forina pustulata Aoh. Lioh. Univ. (1810)
p. 309.
Often confounded with L . leioplaca, from which, among other characters,
it differs in the number of the spores. I t has more the general
aspect of P. communis, but apart from the different thalline reactions,
the verrucæ are smaller and the ostioles less depressed. There is also a
leucostomous state (form superpallens Nyl. Flora, 1886, p. 466) which
has been very sparmgly gathered in Britain.
Hah. On trunks of trees iu wooded upland situations.—Disir. Local
and scarce in E., S. and N. England, and N. Wales.—B. M. Eppiug
Forest, Essex ; New Forest, Hants ; Hinton Abbey, Somersetshire ; GiL
garrón, Cumberland ; Dolgelly, Merionethshire.
B. Thecæ paiioi- or pluri-spored ; spores blackish.
20. P. lactescens Mudd, Man. (1801) p. 272 (exol. var. ft).—
Thallus subdeterminate, thiokish, continuous, a t len g th rugoso-
unequal, rimoso-diffract, greyish or cream-coloured (K + yellow, th en
saffron-red, CaCl—). Apotheoia rugoso-difform, innate in non-
prominent thalline areolæ, brownish-blaok, in ternally subinoolorous ;
spores 2uæ (rarely 3 -4 næ ), olive-hlaokish (K + violet), 0 ,0 9 0 -1 3 0
mm. long, 0 ,0 5 5 -8 5 mm. thiok.—Cromb. Grevillea, xix. p. 59.—
P. spilomanthodes Nyl. Elora, 1881, p. 1 7 9 ; Cromb. Grevillea, x.
p. 23.— B rit. Exs. : Mudd, n. 260.
With the following well characterized by the blacldsh spores, though
Mudd erroneously describes them (iu their immature state) as pale-
yellowish-gteen or pale-yellow. I t comes very near P. spilomantha Nyl.,
a plant of the Eastern Pyrenees, but differs in the normally 2-spored
thecæ aud the smaller spores. The apothecia are rather scattered in the
specimens seen.
Hab. On rocks and walls in upland districts.—Histr. Only sparintey
in a few localities of N. E n g la n d .-B . M. : Aytou Moor, Cleveland,
Yorkshire; Ennerdale, Cumberland.
21. P. urceolaria Nyl. Bull. Soc. Linn. Normand, vi. (1873)
p. 324 (nota).—Thallus effuse, th in , areolato-rimose, subpapilloso-
scabrid, greyish- or yellowish-white (K + yellow, then orange-red,
CaCl — ). Apotheoia small, depressed, uroeolariiform, black ; spores
l-4 n æ , blackish (K + violet), 0 ,1 0 0 -1 4 0 mm. long', 0 ,0 5 0 -7 5 mm
th ick .—Cromh. Grevillea, xix. p. 59 ; Leight. Lich. El. ed. 3, p. 238
pro parte.
An endemic plant easily recognized by the urceolato-depressed apothecia.
I t is allied to the preceding species, but differs in the thallus
being more or less rough with papillæ and iu the form of the fruit. The
two specimens seen are well fertile.
Hab. On granitic stones of a wall iu a maritime district.—Histr. Extremely
local in one of the Channel Is la n d s .-B . M. : La Moye, Island of
Jersey.
C. Thecæ pluri-spored ; spores colourless.
a. Spores 8næ.
22. P. -Wulfenii DC. El. F r. ii. (1805) p. 320.—Thallus de te rminate
or subeffuse, membranaceo-oartiiaginous, thiokish, plicato-
rugose, rimose, whitish- or greyish-yellow (K f+ yellowish, K(CaCl)
+ orange-yellow) ; fertile verrucæ crowded, irregularly depresso-
globose or difform. Apotheoia w ith the ostiola dilated, confluent,
difibrm, subleoanoroid, blackish, undulate and suborenate a t the
margin (epitheoium K + v io le t) ; spores 0 ,0 5 8 -8 5 mm, lo n g ,0 ,0 2 8 -
38 mm. thiok.—Cromb. Grevillea, xix. p. 59.—P. fa lla x (Aoh.)
Sm. Eng. Fl. v. p. 1 6 0 ; Leight. Br. Angio. Lich. p. 29, t. 10.
f. 2 ; Mudd, Man. p. 2 7 6 ; Cromb. Lioh. Brit. p. 6 0 ; Leight.
Lich. El. p. 240, ed. 3, p. 231. Lichen hymenius, Eng. Bot.
t. 1731. Thelotrema hymenium Turn. & Borr. Lioh. Br. p. 185.
Porina hymenea Gray, Nat. Arr. i. p. 495. Porina fa lla x Tayl. in
Maok. E l. Hib. ii. p. 102. Lichenoides verrueosum et rugosum, cinereum,
glabrum Dill. Muso. 128, t . 18. f. 9 pro p a rte .—B r it. Exs. :
Mndd, n. 266 ; Leight. n. 71.