The thallus of R. zwackhiana is composed of scattered to crowded grey-brown areoles to squamules. It is often sterile and sometimes forms irregular soralia. If fertile, it has the grey pigment Sedifolia-grey in epihymenium and thin-walled Buellia-type spores.
The species occurs on calcareous rocks or calcareous silicates, at places protected from rain, typically under rock overhangs. In Europe, it is widely distributed, primarily on xerothermic rocks, but generally is rare. There are several records from southern and central Bohemia: in the Koda reserve in Český kras (the Bohemian karst) and on calcareous rocks near Český Krumlov, where it forms extensive covers of several squared decimetres.
Literature: Vondrák J., Kocourková J., Palice Z. & Liška J. (2006): New and noteworthy lichens in the Czech Republic – genus Rinodina. – In: Lackovičová A., Guttová A., Lisická E. & Lizoň P. [eds], Central European lichens – diversity and threat, p. 109–118. Mycotaxon Ltd., Ithaca.taxonomic classification:
All records: 7, confirmed 6. One click on a selected square displays particular record(s), including their source(s).