Crocinoboletus, a new genus of Boletaceae (Boletales) with unusual boletocrocin polyene pigments

Abstract

Crocinoboletus is described as a new genus of Boletaceae to accommodate Boletus rufoaureus and B. laetissimus, characterized by its brilliant orange color of basidiomata caused by the presence of unusual boletocrocin polyene pigments, bluish olivaceous staining of all parts when bruised, smooth basidiospores, and the pileipellis which has an interwoven trichoderm at the middle part of the pileus and a cutis at the margin of the pileus. Prior molecular phylogenetic analyses also confirmed the two taxa are not members of the genus Boletus s.s., but form a well-supported generic lineage within Boletaceae. Consequently a description, color photos of fresh basidiomata, line-drawings of microstructures and a comparison of Crocinoboletus with allied taxa are presented.