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''Boletus edulis'' (English: cep, penny bun, porcino (plural porcini), or king bolete) 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. The fungus grows in deciduous and coniferous forests and tree plantations, forming symbiotic ectomycorrhizal associations with living trees by enveloping the tree's underground roots with sheaths of fungal tissue. The fungus produces spore-bearing fruit bodies above ground in summer and autumn. The fruit body has a large brown cap which on occasion can reach in diameter and in weight. Like other boletes, it has tubes extending downward from the underside of the cap, rather than gills; spores escape at maturity through the tube openings, or pores. The pore surface of the ''B. edulis'' fruit body is whitish when young, but ages to a greenish-yellow. The stout stipe, or stem, is white or yellowish in colour, up to tall and thick, and partially covered with a raised network pattern, or reticulations. Prized as an ingredient in various foods, ''B. edulis'' is an edible mushroom held in high regard in many cuisines, and is commonly prepared and eaten in soups, pasta, or risotto. The mushroom is low in fat and digestible carbohydrates, and high in protein, vitamins, minerals and dietary fibre. Although it is sold commercially, it is very difficult to cultivate. Available fresh in autumn in Central, Southern and Northern Europe, it is most often dried, packaged and distributed worldwide. Keeping its flavour after drying, it is then reconstituted and used in cooking. ''B. edulis'' is one of the few fungi sold pickled. The fungus also produces a variety of organic compounds with a diverse spectrum of biological activity, including the steroid derivative ergosterol, a sugar binding protein, antiviral compounds, antioxidants, and phytochelatins, which give the organism resistance to toxic heavy metals. ==Taxonomy== ''Boletus edulis'' was first described in 1782 by the French botanist Pierre Bulliard and still bears its original name. The starting date of fungal taxonomy had been set as January 1, 1821, to coincide with the date of the works of the 'father of mycology', Swedish naturalist Elias Magnus Fries, which meant the name required sanction by Fries (indicated in the name by a colon) to be considered valid, as Bulliard's work preceded this date. It was thus written ''Boletus edulis'' Bull.:Fr. A 1987 revision of the International Code of Botanical Nomenclature set the starting date at May 1, 1753, the date of publication of Linnaeus' work, the ''Species Plantarum''. Hence, the name no longer requires the ratification of Fries' authority. Early alternate names include ''Boletus solidus'' by English naturalist James Sowerby in 1809,〔 This entire work is available in Commons here, but the reference is to plate 419 with textual description on page 697. Sowerby described the same modern species as ''B. edulis'' on plate 111 (description on page 57).〕 and Gray's ''Leccinum edule''. Gray's transfer of the species to ''Leccinum'' was later determined to be inconsistent with the rules of botanical nomenclature, and he apparently was unfamiliar with the earlier works of Fries when he published his arrangement of bolete species. ''B. edulis'' is the type species of the genus ''Boletus''. In Rolf Singer's classification of the Agaricales mushrooms, it is also the type species of section ''Boletus'', a grouping of about 30 related boletes united by several characteristics: a mild-tasting, white flesh that does not change colour when exposed to air; a smooth to distinctly raised, netted pattern over at least the uppermost portion of the stem; a yellow-brown or olive-brown spore print; white tubes that later become yellowish then greenish, which initially appear to be stuffed with cotton; and cystidia that are not strongly coloured. Molecular analysis published in 1997 established that the bolete mushrooms are all derived from a common ancestor, and established the Boletales as an order separate from the Agaricales. The generic name is derived from the Latin term ''bōlētus'' "mushroom", which was borrowed in turn from the Ancient Greek βωλίτης, "terrestrial fungus". Ultimately, this last word derives from ''bōlos''/βῶλος "lump", "clod", and, metaphorically, "mushroom". The βωλίτης of Galen, like the ''boletus'' of Latin writers like Martial, Seneca and Petronius,〔Peter Howell, ''A Commentary on Book One of the Epigrams of Martial,'' The Athlone Press, 1980 p.152-3. Howell doubts the identification, and mentions the view advanced by Augusta A. Imholtz Jr., 'Fungi and piace- names, thè origin of boletus,' in AJP Vol.98, 1977 pp.71f., that the Latin word may derive from the Spanish town Boletum, modern-day Boltaña, south of the Pyrenees, which is still famous for its mushrooms.〕 is often identified as the much prized ''Amanita caesarea''. The specific epithet ''edulis'' in Latin means "eatable" or "edible". 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Boletus edulis」の詳細全文を読む スポンサード リンク
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