Boletus edulis (English: penny bun, cep, porcino or porcini) is a basidiomycete fungus, and the type species of the genus Boletus. Widely distributed in the Northern Hemisphere across Europe, Asia, and North America, it does not occur naturally in the Southern Hemisphere, although it has been introduced to southern Africa, Australia, and New Zealand. Several closely related European mushrooms formerly thought to be varieties or forms of B. edulis have been shown using molecular phylogenetic analysis to be distinct species, and others previously classed as separate species are conspecific with this species. The western North American species commonly known as the California king bolete (Boletus edulis var. grandedulis) is a large, darker-coloured variant first formally identified in 2007.