_Habitat_ & _Distribution_: Found in woods, especially accompanying pine trees, but often found fruiting on the site of former coniferous trees, even years after the trunks or the stumps have been removed. _General Information_: This fungus is recognised by the rounded, red-brown cap, coupled with the pale yellow flesh and greenish yellow tubes, both of which become greenish blue when exposed to the air. There are several species in the genus _Boletus_ which stain blue at the slightest touch or when the flesh is exposed to the air, e.g. _B. erythropus_ (Fries) Secretan, a common bolete with a dark olivaceous cap, orange pores and red-dotted stem. The flesh of some species of _Boletus_, e.g. _B. edulis_ Fries, however, remains unchanged or at most becomes flushed slightly pinkish. Although many people say they recognise _B. edulis_, the ‘Penny-bun’ bolete--a name derived from the colour of the cap, there is some doubt as to whether the true _B. edulis_ is common in Britain as we are led to believe. _B. edulis_ and its relatives are highly recommended as edible (see p. 35). _B. badius_ is also edible, but it is ill-advised to eat any bolete which turns blue when cut open. _Illustrations_: _B. badius_--F 38c; Hvass 248 (not very good); LH 191; NB 109⁵; WD 85¹. _B. edulis_: F 42a; Hvass 246; LH 191; NB 143³. General notes on Boletes There are nearly seventy boletes recorded for the British Isles and evidence of others which have as yet not been fully documented. As a group they are characterised by being fleshy, possessing a central stem and producing their spores within the tubes, and not on gills as in the common mushroom. It is the first character by which the boletes differ so markedly from the other pored fungi, such as the ‘Scaly Polypore’ (see p. 140). The boletes have long been classified in the genus _Boletus_, but instead of referring all the pored, fleshy fungi to a single large genus several genera are now recognised. The separation of these genera is based on differences in colour of the spore-print and differences in the anatomy of the tubes, cap and stem, etc., e.g. members of the genus _Suillus_ have colourless or pale coloured dots on the stem exuding a resin-like liquid in wet weather, which is clear and glistening in some species but turbid and whitish in others, gradually darkening and hardening so that the stem is ultimately covered in dark brown or reddish smears or spots; members of the genus _Leccinum_ on the other hand never exude liquid and have coarse or fine roughenings on the stem which are usually dark, but may commence white and ultimately darken depending on the species; many species of _Boletus_ possess a very distinct raised network all over the stem, whilst others have it present only in part, or have minute, often brightly coloured, dots replacing it. [Illustration: Plate 3. Fleshy fungi: Spores borne within tubes]