Three new species of Tomentella (Thelephorales) from Finland, T. globosa, T. lammiensis, and T. longisterigmata, are described and illustrated with morphological characteristics and nuc rDNA ITS1-5.8S-ITS2 sequences. T. globosa is characterized by mucedinoid, pale to dark brown basidiocarps adherent to the substrate, generative hyphae with clamps and rarely with simple septa, and echinulate, globose basidiospores (echinuli up to 1.5 μm long). T. lammiensis is characterized by mucedinoid, oxide yellow to golden brown basidiocarps adherent to the substrate, generative hyphae with clamps and rarely with simple septa, and echinulate, ellipsoid, triangular, or lobbed basidiospores (echinuli up to 2 μm long). T. longisterigmata is characterized by mucedinoid, dark brown to chestnut basidiocarps separable from the substrate, generative hyphae clamped and rarely with simple septa, the long basidial sterigmata (7-11 μm long), and echinulate, globose basidiospores (echinuli up to 2 μm long). An absence of rhizomorphs and cystidia is their common morphological feature. Molecular analyses by maximum likelihood, maximum parsimony, and Bayesian analyses confirm the phylogenetic position of these three new species. The discriminating characters of these new species and their closely related species are discussed in this study, and a key to the species from Finland is provided.
Keywords: ITS; Tomentelloid fungi; phylogeny; taxonomy.