About Caloboletus firmus (Frost) Vizzini
Caloboletus firmus is a bolete fungus that is native to North America. Before 2014, this species was classified under the name Boletus firmus. Updates to the phylogenetic classification framework for the family Boletaceae led to this species, along with several other related boletes such as Caloboletus calopus, being moved to the genus Caloboletus. It was first formally described scientifically in 1874 by American botanist Charles Christopher Frost, based on specimens collected in New England.