Palicella, a new genus of lichenized fungi and its phylogenetic position within Lecanoraceae

Non-saxicolous lecideoid lichens form a diverse and polyphyletic group of species with a worldwide distribution. The phylogenetic relationships of the taxa and major clades are still largely unresolved. Here we introduce a new genus Palicella Rodr. Flakus & Printzen for Lecidea glaucopa Hook. f. & Tayl. and two closely related species. Our molecular phylogenetic results, based on maximum likelihood and Bayesian phylogenetic trees, and a combined dataset of five gene loci (ITS, nrLSU, mrSSU, RPB1 and RPB2), indicate that Palicella forms a monophyletic clade sister to Lecanora symmicta and Pyrrhospora quernea. The new genus is characterized by biatorine apothecia, which are often darkened (by the pigment Cinereorufa-green), an exciple of radiating, narrow hyphae with strongly elongate lumina, a hymenium with branched and sparsely anastomosed paraphyses, an ascus with a broad axial body surrounded by a distinct darker staining layer, and narrowly ellipsoid ascospores. Atranorin is present in all, usnic acid in two and pannarin in one species of the genus. Three new combinations are proposed: Palicella filamentosa (Stirt.) Rodr. Flakus & Printzen, P. glaucopa (Hook. f. & Taylor) Rodr. Flakus & Printzen, and P. schizochromatica (Pe ' rez-Ortega, T. Sprib. & Printzen) Rodr. Flakus & Printzen. The molecular phylogenetic analysis confirms that Lecidea hercynica Hauck & Schmull is a synonym of P. filamentosa. An identification key to the species is provided.