Glaucomaria is a genus of lichen-forming fungi in the family Lecanoraceae.[1] It has seven species. The genus was circumscribed by Maurice Choisy in 1929.[2] It contains crustose lichens formerly placed in the Lecanora rupicola species complex as defined by several previous authors.[3][4][5]

Glaucomaria
Glaucomaria carpinea
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Lecanoraceae
Genus: Glaucomaria
M.Choisy (1929)
Type species
Glaucomaria rupicola
(L.) P.F.Cannon (2022)
Species

G. bicincta
G. carpinea
G. leptyrodes
G. lojkaeana
G. rupicola
G. subcarpinea
G. swartzii

Description

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Glaucomaria is characterised by a crust-like (crustose) thallus, which is sometimes spread out with a radiating pattern (placodioid). The colour of the thallus ranges from white-yellowish green to pale grey. The apothecia (fruiting bodies) initially grow attached (adnate) and can become slightly raised (sessile) or nearly stalked (substipitate). These apothecia feature a heavily powdery (pruinose) disc that reacts to the C spot test to produce an intense lemon-yellow colour. The margin of the apothecia is persistent, sometimes being pushed aside (finally excluded), and occasionally surrounded by a black, wavy (flexuose) ring.[6]

The outer layer of the apothecia (thalline exciple) typically has a phenocorticate cortex (containing hyphal fragments and dead, collapsed algal cells), numerous algal cells, and both large and small crystals, with the latter dissolving in a solution of potassium hydroxide (K). The inner layer (proper exciple) ranges from thin to thick, dark on the outside and upper part but colourless inside. The epithecium (topmost layer of the apothecia) is brown to dark brown with crystals, both the pigment and crystals dissolving in K. The hymenium, the spore-producing layer, is colourless and does not contain oil droplets. The paraphyses (sterile filaments in the hymenium) are slightly thickened at the top. The layer below the hymenium (hypothecium) is colourless and not interspersed with droplets.[6]

The asci (spore-bearing cells) of Glaucomaria are club-shaped (clavate) and very thin-walled. They contain a tall structure in the middle (tholus) that reacts to iodine and potassium hydroxide by turning blue (K/I+ blue), surrounded by a blue outer layer (Lecanora-type). The ascospores are single-celled, hyaline (translucent), ellipsoid, and have a wall less than 1 μm thick. The photobiont, the photosynthetic partner of the lichen, is chlorococcoid a type of green algae (chlorococcoid).[6]

Chemistry

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Glaucomaria contains a variety of compounds including arthothelin, atranorin, chloroatranorin, eugenitol, isoarthothelin, and methyl 3a-hydroxy-4-O-demethylbarbatate. Some species also have sordidone, psoromic acid, thiophanic acid, dichlorlichexanthone, and 2,5,7-trichlornorlichenxanthone. The pruina (powdery substance) on the apothecial disc contains sordidone and occasionally thiophanic acid.[6]

Species

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References

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  1. ^ "Glaucomaria". Catalogue of Life. Species 2000: Leiden, the Netherlands. Retrieved 18 January 2024.
  2. ^ Choisy, M. (1929). "Genres nouveaux pour la lichénologie dans le groupe des Lecanoracées". Bulletin de la Société Botanique de France (in French). 76 (3): 521–527. Bibcode:1929BSBF...76..521C. doi:10.1080/00378941.1929.10837179.
  3. ^ Grube, Martin; Baloch, Elisabeth; Arup, Ulf (2004). "A phylogenetic study of the Lecanora rupicola group (Lecanoraceae, Ascomycota)". Mycological Research. 108 (5): 506–514. doi:10.1017/S0953756204009888. PMID 15230003.
  4. ^ Blaha, J.; Grube, M. (2007). "The new species Lecanora bicinctoidea, its position and considerations about phenotypic evolution in the Lecanora rupicola group". Mycologia. 99 (1): 50–58. doi:10.1080/15572536.2007.11832600. JSTOR 20444806. PMID 17663123.
  5. ^ Zhao, X.; Leavitt, S.D.; Zhao, Z.T.; Zhang, L.L.; Arup, U.; Grube, M.; Pérez-Ortega, S.; Printzen, C.; Śliwa, L.; Kraichak, E.; Divakar, P.K.; Crespo, A.; Lumbsch, H.T. (2015). "Towards a revised generic classification of lecanoroid lichens (Lecanoraceae, Ascomycota) based on molecular, morphological and chemical evidence". Fungal Diversity. 78: 293–304. doi:10.1007/s13225-015-0354-5.
  6. ^ a b c d Nimis, P.L.; Martellos, S. "Glaucomaria". ITALIC 7.0. Retrieved 18 January 2024.