Basionym Name:Boletus firmus Frost, Bull. Buffalo Soc. nat. Sci. 2: 103 (1874)
Homotypic synonyms:Caloboletus firmus (Frost) Vizzini, Index Fungorum 146: 1 (2014)Suillus firmus (Frost) Kuntze, Revis. gen. pl. (Leipzig) 3(3): 535 (1898)