Physconia muscigena (Ach.) Poelt

Physconia muscigena is a sexually reproducing species which probably does not form apothecia any more in the area of the Czech Republic. Thus, it only persists thanks to lateral growth and rare thallus fragmentation; its dispersion to new places is practically impossible. It grows on bryophytes or plant debris on calcareous rocks in primarily open habitats. It also occurs in alpine grasslands. In Europe, the species is locally abundant, e.g., in limestone regions of the Alps and the Carpathians, where it grows from xerothermic to alpine areas. It is very rare in the Czech Republic, documented on diabase in Prague, limestone in the Pálava Hills and calcareous phyllite on the Mt Petrovy kameny in the Hrubý Jeseník Mts. Another published record is from Dolní Kounice in southern Moravia (Nádvorník 1947). Currently, there are only small populations in the Prokopské údolí valley in Prague, one on Petrovy kameny and richer populations in Pálava.

Physcia bayeri (Nádvorník 1947) was circumscribed from diabases in Prague. It differs in the yellowish medulla with a K+ yellow reaction due to secalonic acid A. According to a molecular analysis, it falls within the variability of P. muscigena (Starosta & Svoboda 2020).

Literature: Nádvorník J. (1947): Physciaceae Tchécoslovaques. – Studia Botanica Čechoslovaca 8: 69–124. Starosta J. & Svoboda D. (2020): Genetic variability in the Physconia muscigena group (Physciaceae, Ascomycota) in the Northern Hemisphere. – Lichenologist 52: 305–317.

Ascomycota → Lecanoromycetes → Caliciales → Physciaceae → Physconia