A new genus, Catenarina (Teloschistaceae, Ascomycota), with three species is described from the Southern Hemisphere, supported by molecular data. All species contain the secondary metabolite 7-chlorocatenarin, previously unknown in lichens. Catenarinadesolata is a non-littoral, lichenicolous species found on volcanic and soft sedimentary rock at 190-300 m in and near steppes in southernmost Chile and on the subantarctic island, Kerguelen. Catenarina vivasiana grows on maritime rocks and on rock outcrops in lowland Nothofagus forests, but has also been found at altitudes up to c. 580 m on moss and detritus on outcrops in Tierra del Fuego. The Antarctic species Caloplaca iomma is transferred to Catenarina based on chemical data; it grows on rocks near the coast in maritime Antarctica.