Lecanora horiza (Ach.) Linds.

Trans. Bot. Soc. Edinburgh, 9: 96, 1869. Basionym: Lecanora subfusca var. horiza Ach. - Lichenogr. Univ.: 394, 1810.
Synonyms: Lecanora laevis Poelt; Lecanora oleae Reichert & Galun; Lecanora palestinica Räsänen; Lecanora parisiensis Nyl.; Lecanora sienae B. de Lesd.?
Distribution: N - Emil (Nimis & al. 1996, Benesperi 2009, Fariselli & al. 2020), Lig (Valcuvia & al. 2000, Giordani & Incerti 2008). C - Tosc (Loppi & Putortì 1995, Loppi & al. 1995, 1997, 1997b, 1998, 1998b, 2002, 2002c, 2003, 2004, 2004c, 2006, Loppi 1996, 1996b, Loppi & De Dominicis 1996, Putortì & al. 1998, Putortì & Loppi 1999, Bacci & al. 2000, Benesperi 2000a, Senese & Critelli 2000, Loppi & Frati 2004, Frati & al. 2006b, Paoli & Loppi 2008, Brunialti & Frati 2010, Loppi & Nascimbene 2010, Brunialti & al. 2012b), Marc (Nimis & Tretiach 1999, Frati & Brunialti 2006), Umb (Ravera 2000, Panfili 2000b, Ravera & al. 2006, Panfili 2007), Laz (Bartoli & al. 1997, Loppi & Pirintsos 2000, Massari & Ravera 2002, Ruisi & al. 2005, Ravera 2008b, Ravera & Genovesi 2008), Abr (Recchia & al. 1993, Olivieri & al. 1997, 1997b, Loppi & al. 1999, Nimis & Tretiach 1999, Stofer 2006, Gheza & al. 2021), Mol (Nimis & Tretiach 1999, Caporale & al. 2008, Paoli & al. 2015), Sar (Zedda 2002, 2002b, Zedda & al. 2001, Rizzi & al. 2011). S - Camp (Ricciardi & al. 2000, Aprile & al. 2003b, Nimis & Tretiach 2004, Garofalo & al. 2010, Brunialti & al. 2013, Ravera & Brunialti 2013, Catalano & al. 2016), Pugl (Durini & Medagli 2002, 2004, Grube & al. 2004, Brackel 2011), Bas (Nimis & Tretiach 1999, Potenza 2006, Paoli & al. 2006, Potenza & al. 2010, Brackel 2011), Cal (Puntillo 1996, Incerti & Nimis 2006), Si (Merlo 1993, Nimis & al. 1994, 1995, Ottonello & Salone 1994, Ottonello & al. 1994, 2011, Grillo & Cristaudo 1995, Ottonello 1996, Grillo & Carfì 1997, Grillo 1998, Grillo & al. 2002, 2007b, Grillo & Caniglia 2004, 2006, Caniglia & Grillo 2006b, Brackel 2008b, Liistro & Cataldo 2011).
Description: Thallus crustose, episubstratic, continuous to faintly rimose, white to pale yellowish white, sometimes delimited by a dark prothallus. Apothecia lecanorine, sessile to slightly constricted at base, 0.4-1(-1.2) mm across, with a dark reddish brown, often glossy, flat disc, and a smooth, persistent thalline margin. Thalline exciple corticate, the cortex 15-20 µm thick laterally, expanding to 40-85(-150) µm at base, with fine granules soluble in K (visible under polarized light), clearly separated from the medulla by a crystal-free zone; proper exciple colourless, with crystals soluble in K; epithecium red-brown to orange-brown, the pigment not dissolving in K, without crystals; hymenium colourless; paraphyses not or only slightly thickened at apex; hypothecium colourless, not inspersed with oil droplets. 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 blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 11-17 x (5.5-)6-9(-9.5) µm. Photobiont chlorococcoid. Spot tests: thallus K+ yellow, C-, KC-, P- or P+ pale yellow. Chemistry: atranorin, plus a complex of unknown terpenoids.
Note: a mainly Mediterranean species found on smooth bark of isolated broad-leaved trees, much rarer in the North than in Mediterranean Italy. According to Malícek (in litt.) the synonymisation of L. sienae with L. horiza might prove to be incorrect: although the former is a very variable species, L. sienae would represent a real extreme in its variation range.
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: very rare
Padanian area: absent
Humid submediterranean belt: common
Humid mediterranean belt: very common
Dry mediterranean belt: very common

pH of the substrata:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model
Herbarium samples


P.L. Nimis CC BY-SA 4.0
TSB 16584



P.L.Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (38263)
2008.02.25



P.L.Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (38263)
2008.02.25



P.L.Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (38263)
2008.02.25



A. Moro; Owner: Department of Life Sciences, University of Trieste
Sicilia, TP, Isola di Marettimo
2008.04.05



G. Incerti CC BY-SA 04
TSB 30190


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_3/Lecanora_horiza.htm
France, oct. 2015 - sur Juniperus phoenicea - Anse de l'Ile de Fazzio - Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_3/Lecanora_horiza.htm
France, oct. 2015 - sur Juniperus phoenicea - Anse de l'Ile de Fazzio - Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_3/Lecanora_horiza.htm
France, oct. 2015 - sur Juniperus phoenicea - Anse de l'Ile de Fazzio - Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_3/Lecanora_horiza.htm
France, oct. 2015 - sur Juniperus phoenicea - Anse de l'Ile de Fazzio - Corse


LITERATURE


Brodo, IM/ Vitikainen, O (1984) The typification of Lecanora subfusca (L.) Ach., its varieties, and some of its related taxa published before 1850. Mycotaxon

Vitikainen, O/ Brodo, IM (1985) Proposal to reject Lichen subfuscus L. (lichenized fungi). Taxon

Gams, W (1992) Report of the committee for fungi and lichens: new series, 2. Taxon

BOCH, S./ SPARRIUS, L. B. (2006) Neue und interessante Flechtenfunde aus den Landkreisen Luneburg und Luchow-Dannenberg (Nordost-Niedersachsen, Deutschland).. Herzogia https://blam-bl.de/images/Herzogia_19/H19-Boch-Sparrius.pdf

Dolnik, C./ Abel, H./ de Bruyn, U./ van Dort, K./ Gnuchtel, A./ Neumann, P./ Stolley, G./ Zimmer, D. (2008) Lecanora zosterae und andere interessante Flechtenfunde aus Schleswig Holstein. Kieler Notizen zur Pflanzenkunde

R. Cameron (2009) Are non-native gastropods a threat to endangered lichens?. Canadian Field-Naturalist

Maliček, J. (2014) A revision of the epiphytic species of the Lecanora subfusca group (Lecanoraceae, Ascomycota) in the Czech Republic. The Lichenologist

Christensen, S.N. (2016) Lichenized and lichenicolous fungi from Greece collected by M. Skytte Christiansen, Svend Rungby and other Danish botanists. Herzogia

Mayrhofer, G./ Bilovitz, P.O./ Rohrer, A. (2018) Lichenized and lichenicolous fungi from Croatia kept in the herbarium GZU. Fritschiana

Diederich, P. (2021) Notes on lichenicolous taxa of the asexual fungal genera Intralichen and Trimmatostroma, with a revised key and descriptions of four new species. Herzogia