Abstract
The diabase outcrops are very rich substrates for lichens because of their specific nature. Some species prefer this igneous rock, which is very local within the Czech Republic.
Diabases are only situated in the central part of Bohemia. This paper brings several comments to the occurrence of three selected lichens: Aspicilia dominiana, Physconia muscigena var. bayeri and Toninia physaroides.
All of them grow very rarely in the Czech Republic. Aspicilia dominiana was known from diabase rocks in Prague and Bohemian Karst from the first half of 20th century.
The last records of Physconia muscigena var. bayeri in the country were published in the original description of this taxon (sub Physcia bayeri Nádv.). The last two mentioned taxa have been collected on diabases in Prague recently (Aspicilia dominiana in Motol, Physconia muscigena in Prokopské údolí valley).
A note on Toninia physaroides as a critically endangered species of the lichen flora of the Czech Republic completes this paper.