Lecanora circumborealis Brodo & Vitik.

Mycotaxon, 21: 288, 1984.
Synonyms: Lecanora coilocarpa auct. non (Ach.) Nyl.
Distribution: N - Frl, Ven (Caniglia & al. 1999, Nascimbene & Caniglia 2003c, Nascimbene & al. 2006e, Thor & Nascimbene 2007, Nascimbene & Marini 2007, Nascimbene 2008c), TAA (Nascimbene 2003, 2006b, 2006c, 2008b, 2014, Nascimbene & al. 2005, 2006, 2006e, 2007b, 2008c, 2009, 2010, 2014, 2022, Thor & Nascimbene 2007, Nascimbene & Marini 2015, Nimis & al. 2015, Trindade & al. 2021), Lomb, Piem (Isocrono & al. 2005b), VA (Piervittori & Isocrono 1999), Emil (Fariselli & al. 2020), Lig (Brunialti & al. 1999). C - Abr (Nimis & Tretiach 1999, Corona & al. 2016), Sar. S - Cal (Puntillo 1996).
Description: Thallus crustose, continuous or rimose, yellowish white to pale grey, sometimes delimited by a bluish black prothallus. Apothecia lecanorine, mostly sessile, 0.4-1(-1.5) mm across, with a brown to blackish brown, flat to slightly convex disc, and a usually smooth, persistent thalline margin. Thalline exciple corticate, the cortex very thick, 20-40 µm laterally, 35-65(-90) mm thick at base, the medulla with numerous algal cells, and with large crystals insoluble in K; proper exciple colourless, lacking crystals; epithecium brown to dark brown, the pigment dissolving in K, , with small crystals (<1 μm wide) soluble in K but not in N, penetrating into the epithecium for c. 20 μm, pulicaris-type; hymenium colourless, not inspersed with oil droplets; paraphyses slightly thickened at apex; hypothecium colourless. 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, broadly ellipsoid, 11-18 x 7-12 µm, the wall 1-1.2 µm thick. Photobiont chlorococcoid. Spot tests: K+ yellow, C-, KC-, P- or P+ pale yellow. Chemistry: atranorin (major), chloratranorin, and roccellic acid.
Note: a circumboreal-montane lichen found on acid bark, often on twigs, sometimes on lignum, mostly in upland areas, with optimum in the subalpine belt; common in the Alps, becoming rarer towards the south but reaching the mountains of Calabria.
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

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 38804



Pier Luigi Nimis CC BY-SA 4.0
TSB 38804



Pier Luigi Nimis CC BY-SA 4.0
TSB 38806



P.L. Nimis CC BY-SA 4.0
TSB 38804



Pier Luigi Nimis - CC BY-SA 4.0
TSB 43932


Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php . Courtesy: A. Stridvall



P.L. Nimis CC BY-SA 04
TSB 13736


Walter Obermayer CC BY-SA 4.0 - Source: Lichens of Noricum - http://lichens-of-noricum.uni-graz.at/


Walter Obermayer CC BY-SA 4.0 - Source: Lichens of Noricum - http://lichens-of-noricum.uni-graz.at/


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_5/Lecanora_circumborealis.htm
France, sur écorce de Rhamnus alpina Canyon du crêt de la Neige, alt. 1680 m - Thoiry - Ain
26/8/2017


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_5/Lecanora_circumborealis.htm
France, sur écorce de Rhamnus alpina Canyon du crêt de la Neige, alt. 1680 m - Thoiry - Ain
26/8/2017


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_5/Lecanora_circumborealis.htm
France, sur écorce de Rhamnus alpina Canyon du crêt de la Neige, alt. 1680 m - Thoiry - Ain
26/8/2017


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_L/Texte_L_5/Lecanora_circumborealis.htm
France, sur écorce de Rhamnus alpina Canyon du crêt de la Neige, alt. 1680 m - Thoiry - Ain
26/8/2017