Protoparmeliopsis versicolor (Pers.) M. Choisy

Contr. Lichénogr., 2: no. 13, 1931. Basionym: Lichen versicolor Pers. - Ann. Bot. (Usteri), 1: 24, 1794.
Synonyms: Lecanora alboeffigurata (Anzi) Jatta; Lecanora albomarginata (Nyl. ex Th. Fr.) Cromb.; Lecanora muralis var. albopulverulenta (Schaer.) Rabenh.; Lecanora muralis var. versicolor (Pers.) Tuck.; Placodium albopulverulentum (Schaer.) A. Massal.; Placodium versicolor (Pers.) Frege; Squamaria alboeffigurata Anzi; Squamaria saxicola var. diffracta f. dealbata Anzi
Distribution: N - VG, Frl, Ven, TAA (Nascimbene & al. 2022), Lomb, Piem, VA (Piervittori & isocrono 1999), Emil (Fariselli & al. 2020), Lig. C - Tosc, Marc (Nimis & Tretiach 1999), Umb (Nimis & Tretiach 1999), Laz, Abr (Nimis & Tretiach 1999, Gheza & al. 2021), Mol (Nimis & Tretiach 1999), Sar. S - Camp (Garofalo & al. 1999). Pugl (Nimis & Tretiach 1999), Cal, Si.
Description: Thallus crustose-placodioid, episubstratic, forming orbicular rosettes to 10 cm in diam., pale yellowish green, but often appearing white because of a dense white pruina, areolate in the center, lobed at margins. Lobes 0.5-1(-1.5) mm wide, flat to concave, contiguous, separated by thin white lines, smooth and wax-like, densely white-pruinose; lower surface corticate, dull whitish to pale brown. Upper cortex 50-75 µm (or more) thick, inspersed with yellowish granules soluble in K, insoluble in N, overlain by a 10-15 µm thick epinecral layer filled with colourless crystals; medulla white, rather loose; lower cortex poorly developed, mostly confined to the tips or margins of lobes. Apothecia usually numerous, lecanorine, masking the surface in thallus center, 0.5-1.5(-2) mm across, sessile, with a flat, yellow-brown to ochre-brown disc and a smooth to minutely crenulate, whitish, pruinose, persistent thalline margin (sometimes excluded in very old apothecia). Epithecium pale yellow to brown, with granular crystals not dissolving in K; hymenium colourless, 50-80 µm high, I+ blue; paraphyses coherent, 2-3 µm thick, mainly simple or sparingly branched in upper part, the apical cells not strongly swollen; hypothecium colourless to yellowish. Asci 8-spored, elongate-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, 8-15(-16) x (3-)5-7 µm. Conidia thread-like, straight or curved. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC- or KC+ pale yellow, P-. Chemistry: cortex with usnic acid, medulla with zeorin, and traces of murolic and psoromic acids.
Note: often treated as a calcicolous morph of P. muralis, and hence not always distinguished. However, since it is easily recognisable, and above all because, contrary to P. muralis, it is parasitized by Placocarpus schaereri, I prefer to treat it as a separate species. Widespread on limestone throughout Italy, with optimum below the montane belt. Its status could be solved only by a thorough molecular analysis of the whole complex in Europe. The records are mainly based on herbarium samples in TSB, and on the Italian distribution of the synonyms; several records of P. muralis s.lat. coud refer to this lichen, which is certainly widespread throughout Italy, with optimum below the montane belt.
Growth form: Crustose placodiomorph
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

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



Pier Luigi Nimis; Owner: Department of Life Sciences, University of Trieste
Italy, Friuli Venezia Giulia, Trieste, Trieste Karst, Val Rosandra, San Lorenzo near Belvedere
11/02/2017



Pier Luigi Nimis; Owner: Department of Life Sciences, University of Trieste
Italy, Friuli Venezia Giulia, Trieste, Trieste Karst, Val Rosandra, San Lorenzo near Belvedere
11/02/2017



Pier Luigi Nimis; Owner: Department of Life Sciences, University of Trieste
Italy, Friuli Venezia Giulia, Trieste, Trieste Karst, Val Rosandra, San Lorenzo near Belvedere
11/02/2017


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


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


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


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Corse, Cap Corse


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Corse, Cap Corse


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Corse, Cap Corse


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil


Bernard Bouffinier - Source: http://www.lichensmaritimes.org/index.php?task=fiche&lichen=959&lang=en
France, Pays Basque, Pic de Gorramakil