Sutorius: a new genus for Boletus eximius

Sutorius is described as a new genus of Boletaceae to accommodate Boletus robustus original- ly 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 elonga- tion factor 1a 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