Three new combinations of Butyriboletus (Boletaceae)

Abstract

Boletus peckii, B. pulchriceps and B. roseopurpureus, which were originally described from North America, are characterized by a yellow tube layer that often bruises blue, a yellow reticulated stipe especially at the apex, firm yellow-tinged flesh that often turns blue when exposed, smooth spores and an interwoven trichodermic pileipellis. The phylogenetic positions of the three species are inferred by molecular phylogenetic analysis based on DNA sequences of four gene markers (ITS, nrLSU, tef1-α and rpb1). Both morphological features and molecular phylogenetic evidence indicate that these three boletes belong to Butyriboletus, and thus, should be transferred to the genus.