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''Imperator torosus'', commonly known as the brawny bolete, is a species of bolete fungus in the family Boletaceae. It is native to southern Europe east to the Caucasus and Israel. It is generally associated with deciduous trees such as hornbeam, oak and beech in warm, dry locales. Although generally rare in Europe, it appears to be relatively common in Hungary. Appearing in summer and autumn on chalky soils, the stocky fruit bodies have an ochre cap up to 20 cm (8 in) across, yellow pores on the cap underside, and a wine-red to brown or blackish stipe up to long by wide. The pale yellow flesh changes to different colours when broken or bruised depending on age; younger mushrooms become reddish, and older ones additionally take on bluish tones. Elias Magnus Fries and Christopher Theodor Hök first described this species as ''Boletus torosus'' in 1835, a name by which it was known for many years. Modern molecular phylogenetics shows that it is only distantly related to ''Boletus edulis''—the type species of ''Boletus''—and it was duly placed in the new genus ''Imperator'' in 2015. Eating raw mushrooms of this species leads to vomiting and diarrhea. Gastrointestinal symptoms have also occurred after eating cooked specimens, though some people have eaten it without ill-effects. ==Taxonomy== Swiss mycologist Louis Secretan described the brawny bolete as ''Boletus pachypus'' in his 1833 work ''Mycographie Suisse''.〔 Many of his names have been rejected for nomenclatural purposes because Secretan had a narrow species concept, dividing many taxa into multiple species that were not supported by other authorities, and his works did not use binomial nomenclature consistently.〔〔 Swedish mycologists Elias Magnus Fries and Christopher Theodor Hök described ''Boletus torosus'' in 1835 based on Secretan's ''B. pachypus''—distinct from the ''B. pachypus'' described by Fries himself.〔 Fries reported in his 1838 book ''Epicrisis Systematis Mycologici seu Synopsis Hymenomycetum'' that he had not actually observed the species,〔 and he did not designate a type specimen or illustration.〔 The specific epithet ''torosus'', which derives from Latin, means "muscular".〔 In the United Kingdom, it is known commonly as the "brawny bolete".〔 The German name ''Ochsen-Röhrling'' means "oxen bolete"〔 and the French ''bolet vigoureux'' is "strong bolete".〔 French naturalist Lucien Quélet transferred the species to the now-obsolete genus ''Dictyopus'' in 1886, which resulted in the synonym ''Dictyopus torosus''.〔 ''Boletus xanthocyaneus'', first described by Henri Romagnesi in 1948 as ''Boletus purpureus'' var. ''xanthocyaneus'' and classified as a species in 1976,〔 was considered by Italian mycologist Carlo Luciano Alessio to be synonymous with ''B. torosus''.〔 Others, however, regard this fungus a distinct species.〔〔〔 In 2013 Italian mycologists Valerio Bertolini and Giampaolo Simonini observed that the brevity of the original species description meant that some subsequent papers used ''B. torosus'' for specimens that aligned more closely with descriptions of ''Boletus rhodopurpureus'' or ''B. luteocupreus'' (both now placed in the genus ''Imperator''). They did note that Swiss and French authors had adhered to a more detailed description by Quélet, and that this was the only description faithful to the original description with a grey cap and yellow pores that slowly turn red. They concluded the original description must have been based on specimens growing near the French-Swiss border and hence selected a neotype specimen from this region.〔 Within the large genus ''Boletus'', the brawny bolete was classified in the section ''Luridi'',〔 which included species producing medium to large fruit bodies with thick, swollen stipes, and minute pores.〔 In 1996, Czech mycologist Jiří Hlaváček further subdivided the section ''Luridi'', defining and naming the subsection ''Torosi''—for ''B. torosus''—to contain boletes that strongly bruised blue-black with handling.〔 In a molecular analysis of Boletaceae phylogeny, the brawny bolete was most closely related to ''Boletus luteocupreus''; these two species formed a clade that was sister to ''B. luridus''.〔 Genetic analysis published in 2013 showed that ''B. torosus'' and many (but not all) red-pored boletes were part of a ''dupainii'' clade (named for ''B. dupainii''), well-removed from the core group of ''Boletus edulis'' (the type species of genus ''Boletus'') and relatives within the Boletineae. This indicated that the brawny bolete and its relatives needed to be placed in a new genus.〔 It was made the type species of the new genus ''Imperator'', becoming ''Imperator torosus'', in 2015.〔 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「Imperator torosus」の詳細全文を読む スポンサード リンク
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