English naturalist Miles Joseph Berkeley initially described "Boletus marginatus" in 1845, from the writings and specimens of James Drummond, from the vicinity of the Swan River Colony in Western Australia. Berkeley and Broome described "Boletus portentosus" in a report published in 1873 of the fungi of Ceylon, from a specimen with a 25 cm (8 in) diameter cap collected on June 15, 1869. They held it to be related to "Boletus aestivalis". Microscopic differences led to it being reclassified; Boedijn noted the shape of its spores, lack of cystidia and short tubes and allocated it to the genus "Phlebopus" in 1951. New Zealand botanist Robert McNabb followed Rolf Singer who had determined "Phlebopus" was a nomen dubium (though conceding Singer was likely in error), and coined the binomial "Phaeogyroporus portentosus", by which it was known for some years. In his 1982 review of the genus, mycologist Paul Heinemann used this latter designation. The generic name is derived from the Greek Φλεψ/Φλεβο- "vein", and πους "foot".