Cupreoboletus (Boletaceae, Boletineae), a new monotypic genus segregated from Boletus sect. Luridi to reassign the Mediterranean species B. poikilochromus

Abstract

Cupreoboletus is erected as a new monospecific genus of Boletaceae to accommodate the thermophilic southern European species Boletus poikilochromus, characterized by discoloration toward copper-red tints overall, hymenophore forming tiny crystals on drying, a pervasive and long lasting sweet odor and presence of pseudocystidia. Macro- and microscopic descriptions of the species based on re-examination of the type material and recent Italian collections including additional topotypical samples are provided and accompanied by photos and line drawings of the main anatomical structures. In addition, an epitype specimen is selected. Phylogenetic relationships were inferred from multigene molecular analysis based on partial sequences of the nuc rDNA 28S D1/D2 (28S) and internal transcribed spacer (ITS) regions and genes for ribosomal RNA polymerase II subunits 1 (rpb1) and 2 (rpb2) and translation-elongation factor 1-α (tef1α). Ecological context, geographical range and delimitation from closely allied taxa also were elucidated. B. martaluciae is treated as a synonym of C. poikilochromus according to the morphological and molecular comparative study.

• Basidiomycota
• Boletales
• Boletus martaluciae
• European boletes
• molecular phylogenetics
• taxonomy

Acknowledgments

V. Bertolini (Pisa, Italy) and F. Costanzo (Anguillara Sabazia, Italy) are warmly acknowledged for their useful comments and suggestions. F. Costanzo and V. Migliozzi (Rome, Italy) also are acknowledged by MG for their companionship during field collection. Thanks to A. Zuccherelli (Ravenna, Italy), T. Lezzi (Rome, Italy) and L. Panno (Varese, Italy) for providing us with topotypical material of Boletus poikilochromus, a collection of Cyanoboletus pulverulentus from Azores Islands and electronic scans of the basidiospores, respectively.