Rhizopogon confusus sp. nov., a correct name for a fungus previously recorded in Central Europe as the North American Rhizopogon salebrosus.
Rhizopogon salebrosus, a common species found in western North America, has been recently considered an invasive species in Europe, based on ITS rDNA sequence records from ectomycorrhizal root tips. We collected in montane and submontane coniferous forests (both plantations and unmanaged forests) in the Czech Republic and Slovakia basidiocarps of a species with morphology similar to R. salebrosus. Analysis of sequences of ITS rDNA showed that our collections together with further records from Europe belonged into the R. salebrosus species group. In contrary, they formed a well-supported clade based on analysis of a gene for RNA polymerase II second largest subunit and one anonymous nuclear locus developed for better resolution in the R. salebrosus species group. Evidence from the three genes and distinct phenotypic characteristics show that the European collections represent a novel species within R. salebrosus species group that is described herein as R. confusus. Host affinity of R. confusus, its native presence in Europe and implications for the presumed invasion of R. salebrosus in Europe are discussed.