Recent molecular studies have shown that Boletus in its current circumscription is likely an artificial grouping and it is possible that it will be split at some point into smaller genera. Note that Boletus impolitus and Boletus depilatus for practical reasons are retained here, although there is strong evidence that they are closely related to Xerocomus subtomentosus and its allies.
Fruitbody large to medium sized, boletoid, without veil and ring. Stipe solid, with surface usually covered with granules or network. Flesh variously coloured, changing or not when exposed to air. Tubes easily separable from each other, not tearing apart. Pores usually small and rounded.
Boletus gabretae Pilát
An enigmatic bolete, close to Boletus luridus and especially to its yellow form f. primulicolor Simonini. Boletus gabretae features entirely yellow blueing fruitbodies (cap, stipe, pores, flesh) and is said to grow under conifers. It has been described from the Czech Republic and recorded from Finland and Italy but no recent findings are available. Further search and collections are needed to solve its status.
There are no identifiable photographs available to me or featured online. Colour photographs are published in Pilát (1968) and Pilát & Dermek (1974). Colour paintings are seen in Pilát & Dermek (1974), Engel & al. (1983) and Alessio (1985). The colour illustration, published in Alessio is available online here (opens in new window).
Alessio, C.L. 1985. Boletus Dill. ex L. (sensu lato). – In: Fungi Europaei. Vol. 2. Pp. 1–705. Libreria editrice Biella Giovanna, Saronno.
Engel, H., Krieglsteiner, G., Dermek, A. & Watling, R. 1983. Dickröhrlinge. Die Gattung Boletus in Europa. Verlag Heinz Engel, Weidhausen b. Coburg.
Kallio, P. 1984. Boletus gabretae in Finland. – Karstenia 24: 77–78.
Pilát, A. 1968. Boletus gabretae sp. nov. bohemica ex affinitate Boleti junquillei (Quél.) Boud. – Česká Mykologie 22: 167–170.
Pilát, A. & Dermek, A. 1974. Hríbovité huby. Československé hríbovité a sliziakovité huby (Boletaceae – Gomphidiaceae). Veda, Bratislava.