Boletus is a genus of mushroom, comprising over 100 species. The genus Boletus was originally broadly defined and described by Elias Magnus Fries in 1821, essentially containing all fungi with pores. Since then, gradually other genera have been defined, such as Tylopilus by Petter Adolf Karsten in 1881, and old names such as Leccinum resurrected or redefined.
Some mushrooms listed in older books as members of the genus have now been placed in separate genera. These include such as Boletus scaber, now Leccinum scabrum, Tylopilus felleus, Chalciporus piperatus and Suillus luteus.
The name is derived from the Latin term Bōlētus 'mushroom' from the Ancient Greek βωλιτης, ultimately from bōlos/βωλος 'lump' or 'clod'. However, the βωλιτης of Galen is thought to have been the much prized Amanita caesarea.
Several guidebooks recommend avoiding all red-pored boletes, however both B. erythropus and B. luridus are edible when well-cooked. However, there has been one recorded instance of death from Boletus pulcherrimus in 1994; a couple developed gastrointestinal symptoms after eating this fungus with the husband succumbing. Autopsy revealed infarction of the midgut. Boletus satanas has also long considered to be poisonous, though it has not been responsible for any deaths. The symptoms are predominantly gastrointestinal in nature. A glycoprotein, bolesatine, has been isolated. A similar compound bolevenine has been isolated from the poisonous Boletus venenatus of Japan.
Muscarine has been isolated from some red-pored species, although the amounts are pharmacologically insignificant and unlikely to cause symptoms.