Parmelia pinnatifida Kurok.

The commonest Czech member of the Parmelia omphalodes group. It forms thalli with numerous, usually 1–2 mm wide grey lobes that sometimes gradually turn brown in herbarium specimens. In fresh thalli, brown coloration is usually confined to the lobe tips. Young thalli are rosette-like, but later often develop into extensive patches of imbricate lobes. A typical feature is the concentration of pseudocyphellae along the lobe margins. If pseudocyphellae are also present on the lobe surface, they are usually connected to the marginal ones. However, the species is highly variable, and some parts of a thallus may have broad lobes with isolated laminal pseudocyphellae, thus resembling P. omphalodes.

The species grows mainly on siliceous rocks, including sandstone, gneiss, granite, quartzite and lydite, and often overgrows mosses. Its occurrence on tree bark is very rare. It prefers vertical to slightly inclined rock faces, a humid microclimate and often partial shade. In the Czech Republic, it occurs from the lowlands to the mountains but is most frequent at medium elevations and in submontane and montane areas. In warm regions, this lichen is confined to deep valleys and ravines. Its main areas of occurrence include sandstone rock towns, the Brdy Highlands, the Bohemian-Moravian Highlands, the Krkonoše Mts, the Jizerské hory Mts, the Šumava Mts and the Jeseníky Mts. Overall, the species is practically cosmopolitan.

Literature: Malíček J. & Ludvíková J. (2026): Does Parmelia omphalodes s. str. occur in the Czech Republic? – Bryonora 77: 1–13.

Ascomycota → Lecanoromycetes → Lecanorales → Parmeliaceae → Parmelia