Rehmia furfurosa (formerly Rhizocarpon furfurosum) was historically classified within the genus Rhizocarpon and placed in the brown subgenus Phaeothallus because of the absence of rhizocarpic acid in the thallus. This rare species is found only in Europe and predominantly grows on metal-rich substrates. This species often occurs in a sterile form, making its identification difficult. Here, we report the first records of R. furfurosa in Poland, accompanied by nuITS rDNA sequences of the species from both Norwegian and Polish specimens. In Polish specimens, we observed greater variation in the septation and size of ascospores compared to the protologue, as we found truly muriform ascospores, which are larger than previously reported. In addition, because of the lack of nomenclatural type of Rhizocarpon obscuratum f. granulosum (a synonym of Rehmia furfurosa), a lectotype is here designed. Additionally, by integrating GBIF records with explanatory raster data on heavy metals in European topsoils, we present a species distribution map generated using maximum entropy modelling (MaxEnt). The most significant heavy metal predictors of R. furfurosa were lead, iron, cadmium, zinc, silicon, and aluminum. The final model identified regions with the highest habitat suitability, mainly in mountainous areas, and highlighted potential new locations where the species may occur. Keywords: Rhizocarpales; Phaeothallus; ITS rDNA; spatial analysis; spatial thinning; heavy metals; lectotype.