Micarea pannarica Fryday
Biblioth. Lichenol. 88: 139. 2004
Thallus areolate; areoles creamy white, strongly convex 0.7-1.0 mm across, interspersed with black cephalodia containing Nostoc (cells 3.5-4.0 µm diam.) and amorphous, brown colonies of Stigonema. Photobiont cells globose, thin-walled, 4-7 µm diam., often in pairs (‘micareoid’ sensu Coppins 1983).
Apothecia black or dark brown, lecideine, convex, adnate, margin not visible, 0.8-1.2(-1.4) mm diam., often compound. Excipulum strongly excluded but composed of radiating hyphae, hyaline with dark brown cortical cells. Hypothecium c. 200 µm pale brown above becoming darker below (K—, N+ brighter orange-brown). Hymenium hyaline 70-85 µm, I+ blue; epihymenial zone pale brown (K—, N—), 15-25 µm thick. Paraphyses sparingly branched, 1.5-2.0 µm wide, scarcely swollen at the apices (to 3.5 µm), without pigmented cap. Asci cylindrical, c. 50 x 15 µm, Micarea-type. Ascospores hyaline, 3-septate, 16-19(-21) x 5.5-6 µm.
Conidiomata pycnidia, red-brown, immersed in the areoles, 0.04-0.05 mm diam. Conidia bacilliform, 6-7(-8) x 0.8 Ám.
Chemistry.K—, C—, KC—, Pd+ orange. Pannarin detected by TLC
Ecology and distribution. Micarea pannarica has been recorded only from Campbell Island but has possibly been overlooked elsewhere.
Notes: The new species grows over bryophytes and is a member of the M. assimilata group It can be separated from all other members of the group by the presence of pannarin (Pd+ orange) in the thallus. It is similar to M. magellanica, with which it sometimes grows, but can be separated morphologically from that species by its shorter ascospores and different internal pigmentation. It also has morphological similarities to M. incrassata Hedl., from which it is readily separated by its longer, 3-septate ascospores and its creamy-white (not grey) thallus.
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