ITALIC 8.0

Lecanora hyperpolytropa Cl. Roux & M. Bertrand

in Roux & al., Bull. Soc. linn. Provence, 73: 89, 2022

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Distribution:

Description: Thallus crustose, episubstratic, areolate-subsquamulose, pale yellowish brown, sometimes delimited by a black prothallus. Areoles 0.2-1.7(-2.2) mm wide, 0.2-1 mm thick, flat to slightly convex, more or less round, the largest ones often lobulate, fissurate or glebulose, more or less substipitate, with a central attachment point. Cortex 60-120 μm thick, with a 10-15 μm thick epinecral layer with dead cells and crystals, and a 50-107 μm thick paraplectenchymatous layer which is divided into 2 sub-layers: an upper, 25-42 μm thick, pale brownish yellow layer rich in small yellowish crystals and somehow larger colourless crystals partially soluble in N, totally soluble in K, and a lower, 25-65 μm thick, colourless layer devoid of, or poor in crystals; algal layer continuous or rarely interrupted; medulla 100-800 μm thick, of mostly anticlinally arranged hyphae, with both small and large, colourless crystals soluble in N and insoluble in K. Apothecia lecanorine, (0.3)0.6-2.2(-3.7) mm across, at first round then with a sinuous to almost lobed outline, the largest ones often subdivided into partial apothecia, at first innate then sessile, with a dull, pale reddish brown, smooth or sometimes umbonate, at first concave then convex disc, and a paler, 0.1-0.3 mm thick, at first smooth, then radially split and wavy thalline margin. Thalline exciple 140-230 μm thick in basal part, corticate, without a distinct medulla, the cortex resembling that of thallus; proper exciple colourless, 100-150 μm thick in upper part, of branched hyphae, the upper part paraplectenchymatous, with many small, yellowish crystals insoluble in N and soluble in K, the lower part prosoplectenchymatous, devoid of crystals. Epithecium yellowish brown, 15-22 μm high, with small yellowish crystals insoluble in N and soluble in K, plus a few large, colourless crystals soluble in N; hymenium colourless, 45-60 μm high, I+ blue; paraphyses coherent, simple or sparingly branched and anastomosing, 1.5-2.5 μm thick at base, the apical cells 2-4 μm wide; subhymenium colourless, 22–35 μm, high, without crystals; hypothecium colourless, 120-215 μm high, devoid of crystals. Asci 8-spored clavate, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid to broadly ellipsoid, (8-)9-12.5(-13.5) x (5-)6-7.5(-9) μm, thin-walled. Pycnidia unknown. Photobiont chlorococcoid. Spot tests: cortex and apothecia (disc and margin) K+ yellow, C-, KC+ yellow, P-; medulla K-, C-, KC-, P-. Chemistry: usnic acid and zeorin (major), rangiformic acid (major or minor), plus two unknown compounds.

Note: a recently-described silicicolous species growing on horizontal to vertical surfaces near or above treeline. Known from the French Alps, to be looked for in Italy. The description is based on Roux & al. (2022).

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model

Index Fungorum GBIF

Source: Roux C., Bertrand M., Poumarat S., Uriac P. 2022. Quelques espèces nouvelles saxicoles – calcifuges de Lecanora du groupe polytropa (Ascomycota, Lecanoraceae) découvertes en France. Bull. Soc. linn. Provence, 73: 79-120.