The cetrarioid core group has been the focus of numerous taxonomic and phylogenetic studies in recent years, yet the phylogenetic resolution and support among these clades remains unclear. Here we use four commonly employed loci to estimate if their use increases phylogenetic resolution and support. The present study largely confirms the topologies of previous studies, but with increased support. Approximately half of the genera in the cetrarioid core were not monophyletic. Melanelia sorediella was clustered within Cetrariella, and the combination Cetrariella sorediella (Lettau) V. J. Rico & A. Thell comb. nov. is made. Additionally, the genus Flavocetrariella was supported as part of Nephromopsis and is considered to be a synonym of the latter. Finally, a comparison of genetic distances shows that the maximum intrageneric genetic distance encompassed by many cetrarioid genera is lower than that of many other genera in Parmeliaceae.
