Glaucomaria M. Choisy
Bull. Soc. Bot. Fr., 76: 522, 1929.
Systematics:
Phylum: Ascomycota Caval.-Sm.
Subphylum: Pezizomycotina O.E.Erikss. & Winka
Class: Lecanoromycetes O.E.Erikss. & Winka
Subclass: Lecanoromycetidae P.M.Kirk, P.F.Cannon, J.C.David & Stalpers ex Miądl., Lutzoni & Lumbsch
Order: Lecanorales Nannf.
Family: Lecanoraceae Körb.
Brief description: Thallus crustose, sometimes placodioid, white yellowish green or pale grey. Apothecia lecanorine, at first adnate, then sometimes sessile or substipitate, with a strongly pruinose disc, a persistent or finally excluded thalline margin, and sometimes a black, flexuose parathecial ring, the pruina reacting C+ intensively lemon-yellow. Thalline exciple usually phenocorticate, with numerous algal cells, and with both large and small crystals, the latter soluble in K; proper exciple thin to thick, dark in outer and upper part, colourless within; epithecium brown to dark brown, with crystals, both pigment and crystals dissolving in K; hymenium colourless, not inspersed with oil droplets; paraphyses slightly thickened apically; hypothecium colourless, not inspersed. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a K/I+ blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, the wall <1 µm thick. Photobiont chlorococcoid. Chemistry: thallus with arthothelin, atranorin, chloroatranorin, eugenitol, isoarthothelin, methyl 3a-hydroxy-4-O-demethylbarbatate; some species also have sordidone, psoromic acid, thiophanic acid, dichlorlichexanthone, and 2.5.7.-trichlornorlichenxanthone; pruina of apothecia with sordidone (major), rarely with tiophanic acid.
Note: A rather well-defined genus including the former Lecanora rupicola-group as defined by Grube & al. (2004), Blaha & Grube (2007) and Zhao & al. (2015a), characterized by strongly pruinose, often semi-immersed apothecia containing sordidone, the disc pruina reacting C+ yellow or orange. It appears to occupy a basal clade within the Lecanoraceae. Kondratyuk & al. (2019) wrongly included Lecanora sulphurea. in Glaucomaria but their sequence was actually that of the unrelated Glaucomaria rupicola subsp. sulphurata.
Type: Glaucomaria rupicola (L.) P.F. Cannon
