Evolutionary relationships of Heimioporus and Boletellus (Boletales), with an emphasis on Australian taxa including new species and new combinations in Aureoboletus, Hemileccinum and Xerocomus

Abstract

Boletellus and Heimioporus, two genera of Boletaceae with ornamented basidiospores, are shown to be distinct genera on the basis of phylogenetic analyses of nuclear ribosomal large-subunit and translation elongation-factor 1α DNA sequences. Comparison of spore ornamentation type – longitudinally ribbed in Boletellus v. punctate, alveolate-reticulate in Heimioporus – are further evidence for distinction. Analyses of multiple accessions from the Americas, Asia and Australia support the monophyly of Heimioporus and a ‘core Boletellus’ clade, containing the type species, B. ananas (M.A.Curt.) Murrill, and approximately seven additional species. Tests of alternative phylogenetic topologies could not reject monophyly of a more inclusive group containing the core Boletellus clade and six other species. Heimioporus australis Fechner & Halling, H. cooloolae Fechner & Halling, Boletellus deceptivus Halling & Fechner, B. reminiscens Halling & Fechner and B. sinapipes Fechner, K.Syme, R.Rob. & Halling are described as new species. Phylogenetic analyses also support the following new combinations: Aureoboletus projectellus (Murrill) Halling, A. mirabilis (Murrill) Halling, Hemileccinum subglabripes (Peck) Halling and the new name, Xerocomus tenax Nuhn & Halling.