Two confused Boletes in the Benelux, Boletus impolitus Fries and Boletus depilatus Redeuilh

Boletus impolitus and B. depilatus are known from the Benelux; up to now the latter is found only in Belgium. Both species occur on calcareous soils; B. depilatus, however, seems to prefer soils with a higher calcium content than B. impolitus. The most reliable diagnostic characters are found in the pileipellis, at both the macroscopical and the microscopical level. It is possible that B. depilatus is more thermophilous.