Lecanora austrooceanica
Holotype: New Zealand. Southland, Bluff, S of Ocean Beach, 46º36's, 168º18'30"E, coastal rocks with Carbonea phaeostoma, Tephromela atra and Tylothallia pahiensis, 12.ii.1985, H. Hertel 30808 – M. Isotypes BM, CHR, UPS.
Description : Thallus crustose, rather thick, tartareous, irregularly spreading on coastal rocks, 2–5(–8) cm diam, delimited by a wavy black, prothalline line. Upper surface areolate, areolae angular, 0.5–1.5 mm diam., separated by deep cracks, creamish to dingy grey-white, roughened–papillate to slightly wrinkled. Apothecia sessile, flat on thallus, scattered, solitary to 2–5-clustered together, round to irregular through mutual pressure, disc coal-black, epruinose, to dark green-black with a thin, pale, whitish or creamish pruina, matt, margins slightly raised, concolorous with disc. Anatomy as in L. subcoarctata.
Chemistry : Thallus K+ yellow, C−, KC± orange, Pd−; containing atranorin, ±isoarthothelin, ±thiophaninic acid, ±aeoteaoron, ?dichloronorlichexanthone, ±zeorin (Leuckert in Hertel 1990: 2).
S: Otago (Goat I., Otago Harbour), Southland (near Bluff, Pahia Point). On coastal rocks with Caloplaca cribrosa, C. sublobulata, Carbonea phaeostoma, Pertusaria spp., Physcia nubila, Tephromela atra, Tylothallia pahiensis, Verrucaria durietzii, V. striatula, Xanthoparmelia scabrosa and Xanthoria ligulata. Also in Tasmania (Hertel 1990: 2; Kantvilas 1994b; McCarthy 2003c, 2006; Lumbsch & Elix 2004).
Australasian
Exsiccati : Hertel (1990: No. 224 – isotype).
Lecanora austrooceanica is characterised by: the saxicolous habit (coastal rocks); the thick, tartareous whitish thallus; ±immarginate apothecia or with pale margins; disc concave to plane, black or green-black, with or without a thin, pale pruina. It is somewhat similar to Tylothallia pahiensis, but the thallus is paler and less yellowish and it has Biatora -type asci. Lecanora subcoarctata (q.v.) is similar but differs in the less pruinose apothecial discs and the usually black or only faintly brownish apothecial margins, and the more translucent excipular tisse (in section), and the different xanthone composition (L. subcoarctata has arthothelin and dichloronor-lichexanthone). According to Hannes Hertel (1990: 2) "… Lecanora austrooceanica and L. subcoarctata are both colonising seashore rocks. L. subcoarctata (characterised by ±pruinose apothecia with usually brownish to pale brown margins) seems to be an element of warm temperate coastal regions while the nearly related L. austrooceanica (characterised by less pruinose apothecia with usually black or only faintly brownish margins) seems to be a more cool temperate coastal element…".
