Cladonia foliacea (Huds.) Willd.

A conspicuous species with dominant primary squamules, which are recurved and curly when dry and sometimes have grey-white to black hairs on the margin. The lichen is yellowish, including the pale underside, due to the content of usnic acid. Podetia are rare. Recurling of the squamules when dry protects photobiont cells against excess UV and drying.

Cladonia foliacea is a terricolous lichen associated with open dry stands on both acidic and basic bedrock. It occurs on a wide spectrum of substrates, from sandy to rocky soil. It is typically found in various types of xerothermic grasslands and on rock outcrops. The species is common in Europe, mainly in the Mediterranean, reaching even the warmer areas of northern Europe. In the Czech Republic, it is locally abundant mainly in central Bohemia and south Moravia.

Cladonia convoluta used to be (and still is by some authors) distinguished in the past. However, it is considered an extreme form of C. foliacea on calcareous substrates (e.g., Pino-Bodas et al. 2010). Its distribution in the area of Czechoslovakia was intensively studied by J. Suza (Suza 1925). C. foliacea might be confused with C. luteoalba, which also has conspicuous yellow squamules but is associated with cold climate and forms smaller conspicuously tomentose squamules.

Literature: Pino-Bodas R., Martín M. P. & Burgaz A. R. (2010): Insight into the Cladonia convoluta-C. foliacea (Cladoniaceae, Ascomycota) complex and related species, revealed through morphological, biochemical and phylogenetic analyses. – Systematics and Biodiversity 8: 575–586. Suza J. (1939): Cladonia convoluta Lam. in der Flechtenflora des tschecho-slowakischen xerothermen Gebietes. – Věstník Královské české společnosti nauk 1938/22: 1–40.

Ascomycota → Lecanoromycetes → Lecanorales → Cladoniaceae → Cladonia