The new genus Nimisora Pérez-Ort., M. Svenss. & J. C. Zamora is introduced to accommodate a puzzling lecideoid epiphyte common in the central Iberian Peninsula. Nimisora is characterized by the following combination of characters: lecideoid apothecia, excipulum composed of sparingly branched radiating hyphae with narrow lumina, thick walls and swollen terminal cells, the presence of a brown K+ olivaceous green pigment in the epihymenium, an ascus tip similar to the Bacidia-type, and the presence of simple ellipsoid ascospores. Molecular analyses based on nrITS, nrLSU and mtSSU sequences unequivocally place the new genus within the Lecanoraceae; however, its phylogenetic affinities with other genera of the family remain largely unresolved. Comparisons with the morphologically closest genera are provided. The single species of the genus, Nimisora iberica Pérez-Ort., Turégano, M. Svenss. & J. C. Zamora sp. nov., is also described as new to science.