A rare microlichen, visually and ecologically similar to the common M. peliocarpa, from which it can be reliably distinguished only by microscopical characteristics. The species has a suboceanic distribution and its occurrence in the Czech Republic is linked to consistently humid areas, where it prefers moist valleys and old-growth forests. Historically, the lichen was documented from only two localities. The first record comes from the area of the oldest Krkonoše reserve 'Gehänge' (= Strmá stráň in the Labský důl valley), which is one of the three type localities of the taxon Biatora delicatula Körb. (Körber 1853, Koerber 1855), considered a later synonym of M. cinerea. Here, the lichen was found on root swellings of old spruces. The second record comes from sandstone rocks in the Česká Lípa region between Sosnová and Okřešice, where the species was collected on mosses by J. Anders in 1926. This specimen was identified years later and published in the exsiccate by A. Vězda (Lich. Sel. Exs. n. 1087: Vězda 1972; Coppins 1983). Recently, a few records have been made in forest reserves of the Šumava Mts (Boubínský prales, Zátoňská hora, Bílá strž) and in the Novohradské hory Mts (Žofínský prales). Despite its relative rarity, it is not a substrate-selective lichen (wood, bark, roots, mosses, rocks). The mountain form tenuispora, described from the Alps and known only in a pycnidial stage growing on soil in high mountains, has not yet been documented from the Czech Republic.
Literature: Coppins B. J. (1983): A taxonomic study of the lichen genus Micarea in Europe. – Bulletin of the British Museum for Natural History 11: 17–214. Körber G. G. [recte G. W.] (1853): Sertum Sudeticum, continens novas Lichenum species. – Denkschrift der Schlesischen Gesellschaft für vaterländische Kultur, Breslau, 1853: 231–238. Koerber G. W. (1855): Systema Lichenum Germaniae. Die Flechten Deutschlands (insbesondere Schlesiens), mikroskopisch geprüft, kritisch gesichtet, charakteristisch beschrieben und systematisch geordnet. – Trewendt & Granier, Breslau. Vězda A. (1972): Lichenes selecti exsiccati, editi ab Instituto botanico Academiae Scientiarum Čechoslovacae, Průhonice prope Pragam. Fasc. XLIV. (no. 1076−1100). − Brno.taxonomic classification:
All records: 10, confirmed 10. One click on a selected square displays particular record(s), including their source(s).