Megalaria obludens
Megalaria obludens (Nyl.) Fryday & Lendemer
Lichenologist 42: 599. (2010)
Basionym: Lecidea obludens Nyl., Lich. Fueg. Patag.: 12 (1888).—Catillaria obludens (Nyl.) Zahlbr., Catalogus Lichenum Universalis 4: 21 (1926).
Synonym: Megalaria imshaugii Fryday, Bibliotheca Lichenologica 88: 136 (2004).
Description:
Thallus effuse, variable, typically pale to lead-grey, 0.25-0.4 mm thick, cracked-areolate; areoles 0.7-1.0 mm across, ±flat. Photobiont chlorococcoid, cells globose, 10-15 µm diam.
Apothecia black, lecideine, orbicular, sessile, flat when young but soon becoming convex, 0.7-1.2 mm diam., margin persistent, even in strongly convex apothecia, 0.06-0.08 mm wide. Excipulum of radiating hyphae with enlarged cells (8.5-15 µm diam.), with dark blue pigment on outer walls of the hyphae, continuous under hypothecium. Hypothecium 35 µm thick, dark blue (K+ blue, N+ redHymenium), composed of randomly arranged hyphae. hyaline, 100-120 µm; epihymenial zone dark blue-green (K+ blue, N+ red), 30-35 µm thick; subhymenium ±hyaline, 45-50 µm. Paraphyses simple, readily separating, 2.0-2.5 µm thick, apices swollen to 5.0 µm with dark blue pigmented cap. Asci cylindrical, 80-85 x 15-17 µm, Bacidia-type. Ascospores hyaline, 1-septate, 12-16(-18) x 6-7(-8) µm.
Conidiomata not observed.
Chemistry: no substances detected by TLC.
Distribution:
Common on siliceous rocks on Campbell Island and also occurs on the Auckland Islands and South America (Isla Bucket and the Falkland Islands).
Notes:
Rare on the Falkland Islands. Known only from Hill Cove, West Falkland (West French Peak) and nearby Saunders Island (Rookery Hill)