Acarospora murorum A. Massal.

Mem. Lichenogr.: 130, 1853.
Synonyms: Acarospora dolophana (Nyl.) H. Magn.; Acarospora glaucocarpa var. distans Bagl. & Carestia?; Acarospora macrospora subsp. murorum (A. Massal.) Clauzade & Cl. Roux; Acarospora macrospora var. murorum (A. Massal.) Anzi; Acarospora truncata (A. Massal.) A. Massal.; Biatorella truncata A. Massal.
Distribution: N - VG, Frl. Ven (Lazzarin 2000b), TAA, Lomb, Piem (Isocrono & al. 2003), Emil (Fariselli & al. 2020), Lig (Valcuvia & al. 2000, Watson 2014). C - Tosc, Umb (Genovesi & Ravera 2001, Ravera & al. 2006), Laz (Roccardi 2003), Abr (Nimis & Tretiach 1999), Mol (Ravera & Genovesi 2012, Genovesi & Ravera 2014), S - Si.
Description: Thallus crustose, epilithic, areolate, indeterminate. Areoles 0.7-1.5(-2) mm diam., flat, irregularly rounded or angular, sometimes pruinose, pale brown to sand-coloured when dry, bright green when wet, the underside white. Algal layer 40-70 μm thick, irregularly interrupted by perpendicular strands of medullary hyphae; medulla white in upper part, brownish in lower part. Apothecia 0.5-1 mm across, usually 1 per areole, immersed, with a red-brown to dark brown, concave to flat disc, and a rather prominent thalline margin. Proper exciple colourless, 15-20 μm thick at the base and expanding in upper part; epithecium yellowish brown; hymenium colourless, 110-160 μm tall, I+ blue; paraphyses coherent, septate, 2-3 μm thick at base, 3-5 μm at apex; hypothecium colourless. Asci 30-100-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, ellipsoid, 6-13 x 3-6 μm. Photobiont chlorococcoid. Spot tests: all negative. Chemistry: no lichen substances.
Note: a mild-temperate species, most frequent on walls, gravestones, and monuments below the subalpine belt. Related to A. macrospora, but with a different ecology and altitudinal distribution. The correct name may prove to be A. truncata (A. Massal.) A. Massal. (Arcadia 2016).
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: extremely rare
Submediterranean belt: rare
Padanian area: very rare
Humid submediterranean belt: rare
Humid mediterranean belt: very rare
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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P.L. Nimis CC BY-SA 4.0
TSB 10950



P.L. Nimis CC BY-SA 4.0
TSB 10950