Myriospora scabrida forms a greyish-white to brown thallus, usually composed of rounded to irregularly lobed, often imbricate squamules. They are 0.5–3.5 mm wide, flat to slightly convex, and rarely weakly pruinose. Apothecia are usually 1–7 per squamule, but may be more numerous; they are initially immersed and later become slightly elevated. Their disc is reddish brown to almost black, often rough, and surrounded by a conspicuous, somewhat raised and frequently blackening margin. The thallus contains no lichen secondary metabolites.
The species grows mainly on acidic siliceous rocks, for example on schist, and rarely on soil or among bryophytes. Its overall distribution is poorly known because of confusion with other representatives of the genus. Most European records have been published from northern Europe (Westberg et al. 2011). There are no confirmed records from the Czech Republic. The only published record, from the Hrubý Jeseník Mountains (Knudsen et al. 2021), in fact belongs to M. hilitzeri.
It differs from M. hilitzeri in having more distinctly elevated apothecia with a broad parathecium, which may reach up to 120 μm in width near the surface. Acarospora badiofusca has similar apothecia, but differs in its continuous to nearly continuous algal layer and paraplectenchymatous rather than prosoplectenchymatous cortex.
Literature: Westberg M., Crewe A. T., Purvis O. W. & Wedin M. (2011): Silobia, a new genus for the Acarospora smaragdula complex (Ascomycota, Acarosporales) and a revision of the group in Sweden. – Lichenologist 43: 7–25. /// Knudsen K., Kocourková J., Hodková E. & Schiefelbein U. (2021): A new species of Myriospora (Acarosporaceae) and a report of Myriospora rufescens from Central Europe. – Herzogia 34: 327–338.
taxonomic classification:Ascomycota → Lecanoromycetes → Acarosporales → Acarosporaceae → Myriospora
All records: 1, confirmed 0. One click on a selected square displays particular record(s), including their source(s).