This almost forgotten and rare Rhizocarpon species was described from the surroundings of Rudník in Obří důl glacial cirque in the Krkonoše Mts (Eitner 1911). In 1927, it was collected at the same locality by V. Kuťák (Westberg et al. 2015). The name was later synonymized (Feuerer 1991) with a variable species, nowadays known as R. reductum. It was resurrected in Scandinavia (Westberg et al. 2015), where it is more abundant.
It is a typical ferrophilic species with rust-coloured thallus. It grows at places similar to R. oederi, from which it is distinguished by more sessile, less immersed and regularly round apothecia. The microscopical distinction is more reliable thanks to the muriform spores (Westberg et al. 2015). The majority of its records come from old copper and iron quarries. Recently, it has been confirmed in the Obří důl in Krkonoše Mts.
Literature: Eitner E. (1911): Dritter Nachtrag zur schlesischen Flechtenflora. – Jahresbericht der Schlesischen Gesellschaft für Vaterländische Kultur, Abt. Zool.-Bot., Breslau, 88: 20–60. Feuerer T. (1991): Revision der europäischen Arten der Flechtengattung Rhizocarpon mit nichtgelbem Lager und vielzelligen Sporen. – Bibliotheca Lichenologica 39: 1–218. Westberg M., Timdal E., Asplund J., Bendiksby M., Haugan R., Jonsson F., Larsson P., Odelvik G., Wedin M. & Millanes A. M. (2015): New records of lichenized and lichenicolous fungi in Scandinavia. – MycoKeys 11: 33–61.
taxonomic classification:Ascomycota → Lecanoromycetes → Rhizocarpales → Rhizocarpaceae → Rhizocarpon
Red List (Malíček 2023):DD – data deficient
Occurrence in the Czech Republic
All records: 1, confirmed 1. One click on a selected square displays particular record(s), including their source(s).