Calicium lenticulare Ach.

A variable species, usually with a well-developed pustulate thallus and brown-black, often pruinose apothecia of a characteristic closely obconic to lenticular shape. Under a microscope, the fruiting bodies' margins and their stalks are amyloid (turning blue in reaction to iodine). It grows on snags and trunks of both coniferous and deciduous trees with acidic bark. The species belongs to oceanic, sub-cosmopolitan lichens preferring humid old-growth forests. In Europe it is common only in parts with oceanic climate. For example, in western part of the British Isles it is even accounted frequent (Giavarini & Purvis 2009). In central Europe C. lenticulare is common only in the Alps, otherwise it is a rare species. Regarding the Czech Republic, this lichen has recently been collected from Mt Praděd in the Hrubý Jeseník Mts. However, there is also a historical record on its occurrence on oak wood in the valley of the river Jihlava in the Třebíč region (Nádvorník 1940, as Calicium schaereri). In contrast, the species reported in the same publication from the Hrubý Jeseník Mts under the name C. lenticulare corresponds, according to the description, rather to C. adspersum.

Literature: Nádvorník J. (1940): Systematische Übersicht der mitteleuropäischen Arten der Flechtenfamilie Caliciaceae. – Preslia 18–19: 113–129. Giavarini V.J. & Purvis O.W. (2009): Calicium Pers. (1794). – In: Smith C.W., Aptroot A., Coppins B.J., Fletcher A., Gilbert O.L., James P.W. & Wolseley P.A. [eds], The Lichens of Great Britain and Ireland, p. 241–245, British Lichen Society, London.

Ascomycota → Lecanoromycetes → Caliciales → Caliciaceae → Calicium