Phylogenetic relationships of the neuropogonoid core group in the genus Usnea (Ascomycota: Parmeliaceae)

Species of Usnea with black pigmentation in the cortex and dark apothecial discs are informally referred to as neuropogonoid lichens. Here we studied the phylogenetic relationships of the core group of neuropogonoid lichens using DNA sequence data of three loci: nuclear ITS and IGS rDNA and RPB1. Maximum likelihood and Bayesian analyses revealed monophyly of 11 neuropogonoid species, with U. ciliata and U. subcapillaris forming a separate lineage. The backbone of the phylogeny of the core group was not resolved with statistical confidence, but relationships of groups of two to three species received strong support (U. acromelana +U. aurantiaco-atra; U. messutiae+U. pallidocarpa; U. sphacelata+U. subantarctica+U. trachycarpa; U. lambii+U. perpusilla+U. ushuaiensis). The new combination U. lambii (Imshaug) Wirtz & Lumbsch comb. nov. is made and U. messutiae Wirtz & Lumbsch sp. nov. is described.