Boletus reticulatus

Boletus reticulatus (formerly known as Boletus aestivalis (Paulet) Fr.), and commonly referred to as the summer cep is a basidiomycete fungus of the genus Boletus. It occurs in deciduous forests of Europe where it forms a symbiotic mycorrhizal relationship with species of oak (Quercus). The fungus produces fruiting bodies in the summer months which are edible and popularly collected. The summer cep was formally described by Jacob Christian Schäffer as Boletus reticulatus in 1774, which took precedence over B. aestivalis as described by Jean-Jacques Paulet in 1793. German naturalist Jacob Christian Schäffer described the summer cep as Boletus reticulatus in 1774. Jean-Jacques Paulet described it as Boletus aestivalis in 1793, the species name derived from the Latin aestas 'summer'. The two names were used in literature for many years. Boletus reticulatus is classified in Boletus section Boletus, alongside close relatives such as B. aereus, B. edulis, and B. pinophilus. A genetic study of the four European species found that B. reticulatus was sister to B. aereus. More extensive testing of worldwide taxa revealed that B. reticulatus was most closely related to two lineages that had been classified as B. edulis from southern China and Korea/northern China respectively. The common ancestor of these three species was related to a lineage consisting of B. aereus and the genetically close B. mamorensis. Molecular analysis suggests that the B. aereus/mamorensis and B. reticulatus/Chinese B. 'edulis' lineages diverged around 6 to 7 million years ago.