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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 1a DNA sequences. Comparison of spore ornamentation type -longitudinally ribbed in Boletellus v. punctate, alveolatereticulate 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.

Sutorius is described as a new genus of Boletaceae to accommodate Boletus robustus originally named illegitimately by C.C. Frost from eastern North America. The legitimate name, Boletus eximius, provided by C.H. Peck, has been used since for a dark purple to chocolate brown bolete with finely scaly stipe and reddish brown spore deposit. This iconic taxon has been documented on five continents. Despite the straightforward species identification from morphology, the interpretation of stipe macro-morphology and spore color has led to equivocal generic placement. Phylogenetic analyses of genes encoding large subunit rRNA and translation elongation factor 1α confirm Sutorius as a unique generic lineage in the Boletaceae. Two species are recognized based on multiple accessions: S. eximius, represented by collections from North America, Costa Rica, Guyana, Indonesia and Japan (molecular data are lacking for only the Guyanan and Japanese material); and S. australiensis, represented by material from Queensland, Australia. Additional collections from Zambia and Thailand represent independent lineages, but sampling is insufficient to describe new species for these entities.

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