Arthonia apotheciorum (A. Massal.) Almq.

K. Svenska Vetensk.-Akad. Handl., 17, 6: 58, 1880. Basionym: Sphaeria apotheciorum A. Massal. - Ric. Auton. Lich. Crost., 26, fig. 44, 1852.
Synonyms: Arthonia clemens auct. p.p. non (Tul.) Th. Fr.; Conida apotheciorum (A. Massal.) A. Massal.
Distribution: N - Ven (Lazzarin 2000b, Brackel 2016). S - Pugl (TSB 23181 as A. Clemens, Brackel 2016), Si (Nimis & al. 1994 as A. Clemens, Brackel 2016).
Description: Thallus inapparent, not lichenized, the hyphae developing inside the apothecia of Myriolecis-species, mainly M. albescens. Apothecia arthonioid, immarginate, 0.1-0.4 mm across, at first appearing as small, black dots on the apothecia of the host, then blackening the whole apothecial surface. Proper exciple poorly developed; epithecium dark brown, K+ olive; hymenium colourless, 40-50 μm high, I+ wide-red then blue; paraphysoids 1.5-2 μm thick at mid level, the apical cells 2-4 μm wide, with dark pigmented caps; hypothecium colourless or very pale brown. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large, non-amyloid apical dome, and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, hyaline, narrowly ellipsoid to subclavate, 9-15 x 3-5(-6) µm. Photobiont absent. Spot tests: K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a parasite in the apothecia of Myriolecis albescens and related species, certainly more widespread in Italy; often confused with other related species, especially with A. clemens.
Growth form: Lichenicolous fungus
Substrata: rocks
Reproductive strategy: mainly sexual
paras Myriolecis albescens

Commonnes-rarity: (info)

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


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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Harrie Sipman – Source http://www.bgbm.fu-berlin.de/sipman/Zschackia/AegeanLichens/CaloplacaAC.htm - As Caloplaca oasis