Notes on British Boleti: II.

Summary

A key to the species of the genus Boletus sensu stricto based on habitat, microscopic and macroscopic characters is proposed. Three extra-limital species, as yet unrecorded from the British Isles, B. torosus, B. lupinus Krombh. and B. lupinus s. Bres., are included in the key in the hope that they may appear in future. They may have been overlooked previously or confused with far commoner forms, especially B. luridus, to which many quite distinct species have previously been referred. Also included in the key are three boletes not considered taxonomically to belong to this genus in its strict sense, although in some ways they are superficially similar. The only West European species of Tylopilus is keyed out and its taxonomic position considered. Boletus rubellus Krombh. placed by some American authors in Boletus sensu stricto is also discussed.