Cape York Peninsula, Queensland, Australiaon bark of Melaleuca arcana in a swamp. Coll. K.Thiele, 1985 (CANB)Scale 5 mmThallus corticolous, foliose, ascending, attached by a well-delimited holdfast 25 mm wide, monophyllous, up to 25 mm wide, 0.5 mm thick laterally, to 1 mm thick at the fertile margins. Lobes solid, subrotund, cartilaginous when dry, flaccid when wet, discrete, ascending and often strongly recurved at the margins. Upper surface white, smooth at first, dull to slightly glossy, becoming ribbed, grooved and/or pitted with age, eperforate, lacking vegetative propagules, corticate in part, the cortex 1015 m thick, cartilaginous, of compacted, periclinal hyphae. Lower surface white to pale grey-white, ecorticate, of compacted medullary hyphae in a periclinal arrangement, occasionally indistinctly pitted, lacking anchoring hyphae, rhizines or haptera. Algae beneath the upper surface, forming a combined layer 4075 m thick; cells chlorococcoid, globose, 510 m wide, some rather thick-walled, mixed with long-celled hyphae 34 m wide. Medulla white, a loose network of branched and anastomosing, long-celled hyphae (4)57(8) m wide. Apothecia common, marginal or submarginal, biatorine, stipitate, subglobose, 0.30.6 mm diam.; stipe whitish, 0.31 mm high; disc yellow to yellow-brown, strongly convex to subglobose, glossy, epruinose; proper margin not apparent. Thalline and proper excipulum lacking. Hypothecium 5060 m thick, colourless, not inspersed with granules or oil globules; hyphae variously oriented, anastomosing, thick-walled, 23 m wide, the lumina c. 1 m thick. Hymenium 5075 m thick, colourless, not inspersed, IKI+ blue. Epihymenium 58 m thick, yellow to yellowbrown, decolorized in K, N. Paraphyses agglutinated in the hymenial gel, simple, 11.5 m wide; apical cells yellow or yellow-orange, scarcely swollen in water, (1.5)22.5(3) m wide. Asci clavate, 2125 1013 m, 8-spored but frequently with up to 4 spores aborted, approximating the Cladonia-type (Kantvilas & Elix 1999); apical dome well-developed, amyloid, with a darker-staining central tube with a very narrow, weakly amyloid central zone. Ascospores colourless, simple, narrowly ellipsoid, 59 (2)2.53 m [n = 50]; spore wall smooth. Pycnidia not seen. Chemistry: Cortex K+ yellow; medulla K+ yellow, C, KC; P+ orange; containing atranorin (minor), protocetraric acid (major), convirensic acid (minor), conprotocetraric acid (minor), methyl protocetrarate (minor) by HPLC. Specimen too old for any meaningful, molecular analysis.
