We describe the new lichen species Lecanora austrocalcicola from a limestone outcrop in Brazil, characterized by a verrucose thallus and small apothecia with pale discs with relatively prominent margins that are UV+ yellow, and by the presence of lichexanthone on the apothecium margin. It resembles some species of Myriolecis and Polyozosia but can be distinguished with phylogenetic analyses. Myriolecis, Polyozosia, calcicolous, lichexanthone, tropics