Megaspora verrucosa var. mutabilis (Ach.) Nimis & Cl. Roux

in Nimis, The Lichens of Italy: 430, 1993. Basionym: Urceolaria mutabilis Ach. - Lichenogr. Univ.: 335, 1810.
Synonyms: Aspicilia mutabilis (Ach.) Körb.; Lecanora mutabilis (Ach.) Nyl.; Pachyospora mutabilis (Ach.) A. Massal.; Patellaria mutabilis (Ach.) Trevis.; Pertusaria lapieana B. de Lesd.
Distribution: N - VG, Ven (Nascimbene & Caniglia 2000, 2003c), Lomb, Piem (Isocrono & al. 2004), VA (Piervittori & Isocrono 1999), Emil (Fariselli & al. 2020). C - Tosc (Benesperi 2007), Marc (Nimis & Tretiach 1999), Umb (Ravera 1998, Ravera & al. 2006), Laz (Fornasier & al. 2005), Abr (Recchia & al. 1993, Olivieri & Pacioni 1995, Olivieri & al. 1997, 1997b, Loppi & al. 1999, Nimis & Tretiach 1999, Gheza & al. 2021), Mol (Nimis & Tretiach 1999, Caporale & al. 2008). S - Cal (Puntillo 1995), Si (Grillo 1996).
Description: Thallus crustose, whitish to brownish grey, usually warted, more or less densely white-pruinose, usually rather wwll-delimited. Apothecia frequent, lecanorine, immersed in thalline warts, up to 1.5 mm across (usually less), with a black, initially pore-like then expanded, concave to finally flat, rough but epruinose disc, the black colour expanding to the margin, forming a dark halo; thalline margin thick, smooth, whitish to grey, darker in inner part, pruinose. Thalline exciple with numerous small crystals; proper exciple thin, of strongly conglutinate, vertically aligned hyphae; epithecium olivaceous green to aprtly grey-black, N+ bright green, the darkest parts K+ brownish, without crystals; hymenium colourless, 80-120 µm high, I+ blue; paraphysoids coherent, branched and anastomosing, slender, c. 1.5 µm thick, the apical cells not markedly thickened; hypothecium colourless to yellowish. Asci 6-8-spored, clavate, thick-walled, the outer wall weakly I+ blue, Lecanora-type. Ascospores 1-celled, hyaline, broadly ellipsoid to subglobose, 34-60 x 22-42 µm, the wall 1.5-2.5 µm thick. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: on basal parts of old deciduous trees; most frequent in central Italy; doubtfully distinct from the typical variety.
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

P.L. Nimis CC BY-SA 4.0
TSB 24376

P.L. Nimis CC BY-SA 4.0
TSB 24376