Perithecia simple, globose or semi-globose, black, innate-sessile ;
ostiole poriform ; paraphyses persistent, branched and entangled ;
asci cylindrical, 4-8-spored; spores acicular-fusiform, straight or
bent, 1- pluri-septate, colourless. Spermogones globose or ovoid,
with rod-like spermatia.
Similar to Arthopyrenia, but with acicular spores.
1. L. epidermidis Th. Fr. Lich. Arct. p. 273 (1860).—Thallus
very thin, cream-coloured or greyish, effuse, smooth. Perithecia
elliptical-hemispherical, bursting the bark, black and somewhat
shining; peritheciai wall dimidiate, spreading a t the b a s e ;
paraphyses ra th e r in d is tin c t; spores 8 in the ascus, more or less
curved, 1-5-septate, 0,020-37 mm. long, 0,003-4 mm. thick.—
Lichen epidermidis Ach. Lich. Suec. Prodr. p. 16 (1798). Verrucaria
epidermidis var. albissima Ach. Lich. Univ. p. 276 (1810).
V. oxyspora Nyl. in Bot. Not. 1852, p. 179 ; Cromb. Lich. Bot.
p. 121. V. albissima Nyl. Lich. Scand. p. 282 (1861); Leight.
Lich. Fl. p. 449 ; ed. 3, p. 481. Arthopyrenia oxyspora Mudd
Man. p. 306 (1861).
Exsicc. Mudd n. 299.
Hab. On bark of b irch.—Distr. Eare throughout England, Scotland
and S. and W. Ireland.—R. M. Pease Pottage Gate, Sussex; Thorndon
Hall near Brentwood, E ssex ; Dolgelly, Merioneth ; Hoggart’s Wood,
Ingleby, Cleveland; Swanston AVood, E d inburgh; Glen Falloch,
Perthshire ; Morrone, Braemar, Aberdeenshire ; Killarney, Kerry.
2. L. Carrollii A. L. Sm.—Thallus crustaceous, thin, brownish.
Perithecia minute, black, scattered, hemispherical, immersed a t
the base, opening by a small p o re ; peritheciai wall dimidiate ;
paraphyses slender, branched and en tan g led ; asci elongate-
cylindrical, about 0,090-100 mm. long, 0,010 mm. thick ; spores
8, parallel in the ascus, slender, acicular, indistinctly multi-septate,
0,050-80 mm. long, 0,001-2 mm. thick, straight or variously
bent.
Distinguished by the long slender spores. The perithecia are
rather few and scattered.
Distr. On bark of trees.—R. M. Glenbower, Cork (the only
locality).
115. MICROTHELIA Koerb. Syst. Lich. Germ. p. 372
(1855); emend. Massal. Misc. Lich. p. 57 (1856). (PI. 51.)
Thallus crustaceous, superficial or developed within the substratum,
not corticated. Perithecia small, superficial or semiimmersed,
semi-globose ; paraphyses branched, entangled, sometimes
mucilaginous and disappearing ; asci cylindrical-clavate or
pyriform, 2-8-spored ; spores ovate or elongate-fusiform, usually
1-septate, rarely 3-5-septate, brown. Spermogones globose,
minute, with short rod-like spermatia.
1. M. micula Flot. ex Koerb. Lich. Syst. Germ. p. 373 (1855).
—Thallus pale-whitish-brown, thin, smooth, effuse. Perithecia
minute, black, hemispherical, semi-immersed ; peritheciai wall
dimidiate ; spores 8 in the ascus, dark-brown, oblong, 1-septate,
slightly constricted, the upper cell rather larger, 0,015-25 mm.
long, 0,005-7 mm. thick (usually about 0,017 mm. long,
0,005 mm. thick).— Verrucaria Lyellii Leight. Angioc. Lich.
p. 42, t. 18, fig. 3 (1851)? V. cinerella Plot, ex Nyl. in Maine et
Loire Mém. Soc. Acad. iv. p. 60 (1858) & Lich. Scand. p. 281
(non Nyl. in Ann. Sci. Nat. sér. 3, iii. p. 174 (1 8 5 5 )); Carroll
in Journ. Bot. iii. p. 293 (1865) ; Cromb. Lich. Brit. p. 121 ;
Leight. Lich. Fl. p. 437 ; ed. 3, p. 465.
The species Verrucaria cinerella Nyl. (Ann. Sci. Nat. I. o.) is a
Chilian plant, and has faintly coloured large spores, measuring
0,032-86 mm. long, 0,009-011 mm. thick ; the characters of the
British specimens agree with those republished by Nylander in Lich.
Soand. I. c.
Hab. On trees.—Distr. Eare in S. and W. England, more frequent
in S. and W. Ireland, not recorded from Scotland.—R. M. Sapperton,
Gloucestershire; Glengariff, Cork; Toro Mt., Crogham, Mangerton
and Dinish, Killarney, Lough Inchiquin, Glencar and Old Dromore,
Kerry.
Var. megaspora A. L. Sm.— Similar to the species b u t with
larger spores, 0,023-36 mm. long, 0,009-013 mm. thick—Verrucaria
cinerella var. megaspora Nyl. in Flora li. p. 848 (1868) ;
Cromb. Lich. Brit. p. 121 & in Jonrn. Linn. Soc. xi. p. 490
(1871); Leight. ll. c. Specimen not seen.
Hab. On trees.—Distr. Rare in S. England, New Forest, Hants.
2. M. atomaria Koerb. Syst. Lich. Germ. p. 373 (1855).-—
Thallus thin, greyish. Perithecia minute, hemispherical, semiimmersed,
somewhat shining ; spores ellipsoid-oblong, 1-septate,
dark-brown, small, 0,012—14 mm. long, 0,004—6 mm. thick.
Lichen atomarius Ach. Lich. Suec. Prodr. p. 16 (1/98)?
Verrucaria atomaria DC. PL Franc, ii. p. 313 (1805) ; Leight.
Lich. PL ed. 3, p. 467.
Hab. On bark of hazel, ka.—Distr. Eare in W. Ireland, Kylemore,
Connemara, Galway.
3. M. dispora A. L. Sm.—Thallus greyish-white, pulverulent,
very thin or disappearing. Perithecia minute, 0,150-200 mm. in
diameter, almost globose, shining, black, semi-immersed or almost
superficial, or leaving shallow pits in the substratum ; peritheciai
wall black, ra th e r soft, almost en tire ; paraphyses slender
branched and entangled ; asci elongate-clavate, somewhat
thickened a t the apex, 0,065 mm. long, 0,015 mm. thick,
2-spored ; spores oblong, b lunt or tapering a t one or both ends,