in 2008, a taxonomic revision of western north american populations of this species was published, formally establishing them as a distinct species, "boletus rex-veris". phylogenetic analysis has shown "b. pinophilus" as a member of a clade, or closely related group, with the north american species "b. subcaerulescens", "gastroboletus subalpinus", "b. regineus", "b. fibrillosus", and "b. rex-veris". despite the diverse appearances, these taxa are close genetically, leading feng and colleagues to speculate on combining the first four taxa above as a single species. these four diverged from the lineage that gave rise to "b. fibrillosus" and "b. rex-veris" around 5 million years ago.