Bulletin of the British Museum (Natural History)
Bulletin of the British Museum (Natural History)
Bulletin of the British Museum (Natural History)
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114 BRIAN JOHN COPPINS<br />
al, <strong>of</strong>ten faintly biguttulate and slightly constricted in <strong>the</strong> middle, 3-5-4-5xl-2-l-6 /xm; (b)<br />
sessile on <strong>the</strong> thallus or old apo<strong>the</strong>cia, c. 30-40 /xm diam, with dark reddish brown walls, K— or<br />
dulling; conidia (microconidia) narrowly cylindrical, (3-2-)3-6-4-5x0-7-0-9 /xm.<br />
Chemistry: Thallus K— , C—<br />
detected by t. I.e.<br />
, PD—<br />
; sections <strong>of</strong> thallus and apo<strong>the</strong>cia C-; no substances<br />
Observations: Micarea anterior is characterised by its reddish brown apo<strong>the</strong>cia, ra<strong>the</strong>r<br />
narrow, mostly 1-septate spores, pale pycnidiophores bearing dark brown pycnidia, and a ±<br />
endoxylic, or thin and irregularly verrucose, thallus. Stalked pycnidia are a feature <strong>of</strong> several<br />
o<strong>the</strong>r hgnicolous species (e.g. M. melaeniza, M. misella, M. nigella, and <strong>the</strong> occasionally<br />
lignicolous M. botryaides), but in those species <strong>the</strong> pycnidiophores appear black and have<br />
different pigmentations when examined microscopically. The pycnidiophores <strong>of</strong> M. hedlundii<br />
are brownish but distinctly tomentose, and those <strong>of</strong> <strong>the</strong> normally corticolous M. pycnidiophora<br />
and M. stipitata are entirely hyaline. M. adnata has its mesoconidia produced in immersed<br />
pycnidia and has macroconidia borne on small apo<strong>the</strong>cia-like sporodochia; fur<strong>the</strong>r distinguishing<br />
features from M. anterior include a ± waxy appearance <strong>of</strong> <strong>the</strong> whole plant, mostly<br />
paler apo<strong>the</strong>cia, and relatively broader spores with rounded apices. Richly fertile specimens <strong>of</strong><br />
M. anterior could be confused with Catillaria erysiboides {q. v. ) but that species has marginate<br />
young apo<strong>the</strong>cia, short ovoid spores, and a non-micareoid phycobiont.<br />
Habitat and distribution: M. anterior is found on <strong>the</strong> ra<strong>the</strong>r s<strong>of</strong>t and smooth lignum <strong>of</strong><br />
decorticate trunks <strong>of</strong> Picea and Pinus, and associated with such species as Cetraria pinastri,<br />
Cladonia spp., Hypogymnia physodes, Lecidea icmalea, Lepraria incana agg., Micarea adnata,<br />
M. contexta, M. misella, M. prasina, Parmeliopsis ambigua, P. hyperopta, Pertusaria pupillaris,<br />
and <strong>the</strong> non-lichenised Cryptodiscus pallidas. It is a rare or overlooked species, apparently<br />
confined to Scandinavia, from where it is known from several locahties in middle and sou<strong>the</strong>rn<br />
Sweden, and south-west Finland.<br />
Exsiccata: Malme Lich. Suec. 22 (M, S).<br />
4. M. assimilata (Nyl.) Coppins, comb. nov.<br />
(Fig. 9; Map 3)<br />
Lecidea assimilata Nyl., Lich Scand.: 221 (1861). Type: Norway, Nordland, Helgeland, M. N. Blytt<br />
(H-NYL 16556- lectotype!).<br />
Lecidea assimilata a. [var.] irrubata Th. Fr., Lich. Scand. 2: 522 (1874); nom. inval. (Art. 26).<br />
Thallus growing on bryophytes, plant debris or sandy soil, composed <strong>of</strong> confluent, irregular,<br />
convex-verrucose, sometimes flattened and subeffigurate areolae that are <strong>of</strong>ten intermixed with<br />
cephalodia. Areolae white or brownish white, matt or sometimes glossy, 0-08-0-4 mm diam; in<br />
section, sometimes with a hyaline amorphous covering layer up to 7 /xm thick, outermost hyphae<br />
hyahne; a ± algal-free medulla sometimes differentiated in large areolae. Thallus hyphae c.<br />
T8-3 /xm diam. Phycobiont micareoid, cells 4—7 fxm diam. Cephalodia <strong>of</strong>ten present, irregularly<br />
globose and hidden amongst <strong>the</strong> areolae, sometimes visible externally as brown areolae-like<br />
structures, 0-2-0-4 mm diam; containing Nostoc, cells 3-5 fxm diam. Less <strong>of</strong>ten present are<br />
irregular, ra<strong>the</strong>r loose clusters (? cephalodia) <strong>of</strong> Stigonema.<br />
Apo<strong>the</strong>cia numerous, immarginate, convex to subglobose, matt or ± glossy (subnitid),<br />
0-3-0-8 mm diam, sometimes forming tuberculate clusters up to T5 mm diam. Hymenium,<br />
45-50 /xm tall; upper part (epi<strong>the</strong>cium) dark aeruginose, olivaceous or brownish-green, K—<br />
HNO3+ red; mid-hymenium dilute greenish; lower hymenium dilute greenish and K— , or dilute<br />
purplish and K-l- purple intensifying or K-l- sordid green. Asci clavate, 45-50x 12-14 /xm. Spores<br />
oblong-ellipsoid to oblong-fusiform, 0(-l)-septate, (10-)12-16(-19)x3-5 /xm. Paraphyses<br />
numerous, simple below, but <strong>of</strong>ten forked or branched above, 1-5-1 •7(-2) jxm wide, sometimes<br />
widening above to 3 /xm; apical walls hyaline although surrounded by densely pigmented<br />
gel-matrix. Hypo<strong>the</strong>cium c. 150-400 /xm tall, dark purple brown, K-t- purple intensifying or<br />
(especially in upper part) K-l- dark green; all parts HNO3-I- purple-red; hyphae interwoven but<br />
,