The phylogenetic relationships amongTirmaniawere investigated using the internal transcribed spacer (ITS) and large subunit (LSU) regions of the nuclear-encoded ribosomal DNA (rDNA) and compared with morphological and bioclimatic data. The combined analyses of forty-oneTirmaniasamples from Algeria and Spain supported four lineages corresponding to four morphological species. Besides the two previously described taxa,Tirmania pinoyiandTirmania nivea, here we describe and illustrate a new species,Tirmania sahariensissp. nov., which differs from all otherTirmaniaby its distinct phylogenetic position and its specific combination of morphological features. We also present a first record ofTirmania honrubiaefrom North Africa (Algeria). Our findings suggest that restrictions imposed by the bioclimatic niche have played a key role in driving the speciation process ofTirmaniaalong the Mediterranean and Middle East.