The phylogeny and classification of Neuropogon and Usnea (Parmeliaceae, Ascomycota) revisited

The phylogeny of usneoid lichens with black pigmentation in the cortex was reconstructed using Bayesian and maximum parsimony analyses of nuclear ITS rDNA sequences. Fifty new partial sequences of 14 taxa were generated and assembled with 74 sequences from GenBank. Our results indicate that Neuropogon is polyphyletic with a core group nested within Usnea subgen. Usnea as sister-group to section Usnea. In addition an undescribed species is basal to the section Usnea clade and the Neuropogon species U. acanthella and U. durietzii have unresolved relationships in the Usnea subgen. Usnea clade. Monophyly of Neuropogon not nested within Usnea subgen. Usnea is rejected using three independent tests. Consequently, it is proposed to synonymise Neuropogon with Usnea. We recommend a conservative approach regarding nomenclatural changes from phylogenetic studies especially at the generic level when few taxa are studied.