Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of darkred basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely laceraterimose with age.Keywords Boletales Á Japanese mycobiota Á Taxonomy Boletus section Luridi Fr. is well delimited in the genus macromorphologically in the boletoid habit, the small, often discolored, pores, and the reticulate or finely furfuraceous stipe surface (Singer 1986). The species of the section Luridi are mainly distributed in North America

Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of darkred basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely laceraterimose with age.