Molecular data confirm that Omphalina foliacea is a lichen-forming basidiomycete.

We examined the phylogenetic position of Omphalina foliacea and its putative closest relative, the lichen-forming basidiomycete Lichenomphalia lobata. Both species are restricted to specific habitats in the high andine regions of tropical America. We generated nuclear ITS and LSU rDNA sequences of two collections of each species and analysed the data together with sequences of omphalinoid basidiomycetes retrieved from GenBank using a Bayesian and a maximum parsimony approach. Our analyses show that both, O. foliacea and L. lobata are lichenized basidiomycetes. L. lohata is related to other species of the genus Lichenomphalia, whereas O. foliacea is not closely related to other Omphalina or Lichenomphalia species, but probably belongs in the hymenochaetoid clade. The analysis of a nuclear LSU data set of a broader sampling of hymenochaetoid basidiomycetes supported the placement of O. foliacea in this clade, but did not reveal any close relative.