Myriospora scabrida (Hedl. ex H. Magn.) K. Knudsen & Arcadia

in Arcadia & Knudsen, Opuscula Philolichenum. 11: 22. 2012.. Basionym: Acarospora scabrida Hedl. ex H. Magn. - Göteborg. Vetensk.-och Vitter.-Handl., Ser. 4, 28, 2: 55, 1924
Synonyms: Silobia scabrida (Hedl. ex H. Magn.) M. Westb.; Trimmatothelopsis scabrida (Hedl. ex H. Magn.) Cl. Roux & Nav.-Ros.
Distribution: C - Tosc (Nascimbene & al. 2021).
Description: Thallus crustose-areolate to subsquamulose, the areoles round in outline, at first bullate, smooth, scattered to crowded, becoming subsquamulose, incised to irregularly lobate, often imbricate, the fertile ones 0.5-3.5 (-7) mm wide, pale grey to brown, occasionally partly white-pruinose, flat to slightly convex. Epicortex 10-23 μm thick; cortex paraplectenchymatous, of isodiametric cells, without crystals; algal layer interrupted by thick anticlinal bundles of medullary hyphae; lower cortex absent. Apothecia cryptolecanorine, rounded, 0.2-1(-1.8) mm across, at first immersed but the mature ones distinctly raised above the thallus, 1-7(-12) per areole, with a red-brown to almost black, flat, often scabrid, epruinose disc surrounded by a distinct, somewhat raised, often blackened parathecial margin, the thalline margin poorly developed. Proper exciple colourless to yellow-brown, the uppermost cells with golden to dark brown caps; epithecium dark golden brown to dark red-brown; hymenium colourless, 100-170 μm high; paraphyses 1.5-2 μm thick at mid-level, the apical cells to 4 μm wide; hypothecium colourless, yellowish or pale brown, densely inspersed with oil droplets. Asci 100-200-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, ellipsoid, 3-5 x 1.5-2 μm. Pycnidia rare. Conidia ellipsoid to subglobose, 1.5-2.5 x c. 1 μm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a species with an epilithic thallus consisting of pale grey to pale brown areolate to subsquamulose areoles, and 1-2 mm wide apothecia with brown, somewhat raised discs; usually on acidic schistose rocks .
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: absent
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: extremely rare
Humid mediterranean belt: extremely rare
Dry mediterranean belt: absent

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model

Leif Stridvall - Source:
Courtesy: Anita Stridvall

Magnusson A. H. (1935) Acarosporaceae, Thelocarpaceae. - In: Rabenhorst G. L.: Kryptogamen-Flora von Deutschland, Österreich, und der Schweiz-. 2nd- IX. Die Flechten. Abt. 5- 1. Gebr. Borntraeger. Leipzig, pp. 1-318. – Public Domain

Leif Stridvall - Source:
Courtesy: Anita Stridvall

Leif Stridvall - Source: Courtesy: Anita Stridvall

Courtesy Danièle et Olivier Gonnet - Source:
France, session AFL 2010 - Hérault