Bulletin of the British Museum (Natural History)

LICHEN GENUS MICAREA IN EUROPE 171
Patellaria salevensis Miill. Arg. (= Bacidia salevensis (Mull. Arg.) Zahlbr.). Miiller presumably regarded
Naegeli's manuscript name as a synonym of his new species. B. salevensis (type in BM!) is a limestone
species and is not a Micarea. As indicated by James (1965: 103) the first legitimate publication of the epithet
'trisepta' for a Bacidia-\\kt species is that by Hellbom {loc. cit). By including the epithet in Bilimbia as '5.
trisepta (Naeg.)', Hellbom was clearly using it in its traditional sense and not introducing it as an entirely
new name. There is no indication that any of the authors using the epithet 'trisepta Naeg.' had seen
Naegeli's original material, and no such material has been found amongst Hepp's collections at BM.
Because the original material is probably no longer in existence, neotypification is required. The epithet
'trisepta'' has been a long source of confusion, being used by various authors for several species, especially
Micarea lignaria, M. melaena, M. nitschkeana, M. peliocarpa, and M. ternaria. However, it is clear from
the descriptions and cited specimens in Stizenberger (loc. cit.), Bausch (loc. cit.), Hedlund (1892), and
Vainio (1922) that the epithet 'trisepta' has most commonly been applied to the species now called Micarea
peliocarpa. Because 'trisepta' first appeared in the protologue of a saxicolous species the neotype chosen is
an example of Hepp Flecht. Eur. 510 which was cited under, or in connection with, 'trisepta' in the
treatments of Stizenberger, Bauch, Hedlund, and Vainio.
Thallus effuse, sometimes partly endocuticular, endophloeodal or endoxylic, more usually
developed on the surface of the substratum as rounded, shallow-convex, hemispherical, or ±
globose areolae. Areolae scattered or more usually ± continguous, greenish white, or greywhite
to blue-grey, occasionally becoming dark grey, often dark coloured on upper surface but
pale and greenish white below, matt or slightly glossy, c. 40-200 ixm diam. Areolae in section,
ecorticate but with an amorphous hyaline covering layer c. 2-5 /x,m thick; outermost hyphae
often with grey-green to blue-green walls, K-, HNO3+ red. Phycobiont micareoid, cells 4-7
/xm diam.
Apothecia scattered or more usually crowded and often contiguous, adnate, plane to convex,
sometimes becoming tuberculate; sometimes with an indistinct margin that is flush with the level
of the disc; rarely (as in shaded corticolous forms) whitish or ivory-white, usually pale lead-grey
to grey-black, sometimes grey-brown, often whitish or paler at the margin; (0-12-)0- 14-0-4
(-0-6) mm diam, or to 1 mm when tuberculate. Disc finely roughened, matt, or slightly glossy
(when black); margin (when evident) smooth and often more glossy than the disc. Hymenium
40-55 iJLm tall, usually olive-green or aeruginose (K— , HNO3-I- red) in upper part and ± hyaline
below; in dark coloured apothecia the green pigment often occurs as vertical streaks through the
hymenium. Asci clavate c. 40-55x12-17 /xm. Spores fusiform, clavate-fusiform, or oblongfusiform,
often slightly curved, (l-)3(-5)-septate, (ll-)15-23(-24)x3-5(-6) /am. Paraphyses
numerous, branched, often anastomosing, 1-1-5 /xm wide; apices often more richly branched
and entangled, often slightly incrassate to c. 1-8 /xm, or to 2-5 /i,m due to thickening by green
pigment. Hypotheciumc. 40-70 />im tall, hyaUne or dilute straw; hyphae interwoven, c. 1-1 -7 /xm
wide; ascogenous hyphae with swollen cells c. 2-4 /xm wide. Excipulum well developed, hyaline,
or dilute straw in part, of richly branched and anastomosing, radiating hyphae c. 1-1-5 ^im.
Pycnidia frequently present (especially on bark or lignum), of two types: (a) immersed in
areolae, white or greenish around the ostiole, 140-200 /xm diam, ostiole often widely gaping;
conidia (macroconidia) markedly curved and often sigmoid, often faintly 1-5-septate, 21-40(-
50)x 1-1-5 fim; (b) ± sessile, white, 50-80 /xm diam, ostioles not, or only slightly, gaping;
conidia (microconidia) narrowly fusiform-cylindrical, (5-)6-7(-7-7)x0-4-0-7 /xm.
Chemistry: Thallus and whitish apothecia K-, C-lorange-red;
t.l.c: gyrophoric acid.
red, PD— ; apothecia in section C-l-
Observations: M. peliocarpa occurs in a wide range of habitats and is concurrently variable,
especially regarding the colour of its apothecia and thallus. This variation is considered to be
phenotypic, being due to the amount of green pigment produced in the hymenium and near the
surface of the thallus in response to environmental factors, particularly light. When on the bark
of old trees in sheltered woodland the apothecia are often very pale to blue-grey, more scattered
than usual, and accompanied by numerous pycnidia; such forms are frequent in the ancient
woodlands of the New Forest, Hampshire. There is some variation as to the production of
areolae, these being often poorly developed or even absent when on cortex or lignum, and