Acolium sessile (Pers.) Arnold

A highly specialized lichenicolous lichen, strictly linked to epiphytic members of the genus Pertusaria, most often to the species Pertusaria coccodes. In Europe, this species has a suboceanic distribution and usually occurs in lowland open forests, parks and alleys, typically on the bark of old oaks. Occurrence in the Czech Republic is insufficiently known, uncertain, and de facto unproven, but at least its historical presence in the country is very probable. The absence of this species from the Czech Republic in monographic studies is suspicious (Nádvorník 1942, Tibell 1971). Lisická (1981) summarised all literary data from the former Czechoslovakia, most of which comes from the 19th century. However, from the territory of the Czech Republic she revised only one available Kovář’s specimen from the Žákova hora Hill, which belongs to the rare species Acolium karelicum. The old records mentioned by Vězda & Liška (1999), where spruce appears as a substrate, possibly refer to our two remaining members of the genus Acolium, or to the non-lichenized fungus Microcalicium disseminatum.

Literature: Nádvorník J. (1942): Systematische Übersicht der mitteleuropäischen Arten der Flechtenfamilie Caliciaceae. − Studia Botanica Čechica 5: 6−46. Lisická E. (1981): O výskyte lišajníka Cyphelium sessile (Pers. ex Mérat) Trevis. v Československu. − Zprávy Československé Botanické Společnosti 16: 58−60. Vězda A. & Liška J. (1999): Katalog lišejníků České Republiky. – Botanický ústav AV ČR, Průhonice.

Ascomycota → Lecanoromycetes → Caliciales → Caliciaceae → Acolium