A crustose epiphytic or epixylic microlichen with a rather oceanic distribution. It may be locally abundant in afforested areas of north-western Europe, but it is relatively rare in continental Europe. There are several historical reports on its occurrence in the Czech Republic which need a revision since the taxon used to be often wrongly interpreted in central Europe. For example, all the data collected by M. Servít belong to other species of microlichens with lecideoid or biatorine apothecia (Palice 1998). Cliostomum griffithii is recognisable thanks to the often pruinose, lecideoid fruiting bodies, narrowly ellipsoid one-septate ascospores, and especially thanks to the always present prominent pycnidia, which wall turns purple in KOH (Ekman 1997). The single Czech record comes from the bark of Acer pseudoplatanus in the locality Jilmová skála in the Šumava Mts.
Literature: Palice Z. (1998): Poznámka k identitě některých sběrů lišejníků M. Servíta v herbáři PRC. – Bryonora 21: 11–13. Ekman S. (1997): The genus Cliostomum revisited. – Symbolae Botanicae Upsalienses 32: 17–28.
taxonomic classification:Ascomycota → Lecanoromycetes → Lecanorales → Ramalinaceae → Cliostomum
Red List (Liška & Palice 2010):CR – critically endangered
Red List (Malíček 2023):C1 – critically endangered
Occurrence in the Czech Republic
All records: 3, confirmed 2. One click on a selected square displays particular record(s), including their source(s).