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 flavosanguineus Lavorato & Simonini
Known to me only from the literature. Cap up to 7 cm, convex to flat-convex or almost flat, dry, smooth, lemon yellow to bright yellow, spotted reddish, vinaceous or brownish. Stipe almost cylindrical, often tapering towards the base, lemon yellow to yellow, tinted reddish or vinaceous at the base, covered with fine network. Flesh lemon yellow, blueing when exposed to air. Tubes lemon yellow to yellow with olivaceous tint, blueing when injured. Pores lemon yellow to yellow with olivaceous tint, blueing when bruised. Smell not distinctive. Taste slightly acid. Spores 12.9–14.6 × 5.7–7 μm, ratio 1.8–2.3. Pileipellis (the cap cuticle) a trichodermium of interwoven septate hyphae of cylindrical, not incrusted cells. Chemical reactions: hyphae of the flesh in the stipe base strongly amyloid with Melzer’s reagent.
Habitat. Warm mixed forests with beech (Fagus sylvatica), sweet chestnut (Castanea) and pine (Pinus calabrica).
Distribution. Mediterranean/Southern species, so far known with certainty only from Italy, possibly also in Greece.
Some more colour photos and B&W drawing of microscopic features are available on Sentieri Boschivi. See also the paper of Lavorato & Simonini (1997; available here as MS Word-file), where the species is originally described.
Galli, R. 1998. I Boleti. Atlante pratico-monographico per la determinazione dei boleti. Edinatura, Milano.
La Rocca S. & Genduso E. 2002. Specie rare e poco conosciute: Boletus flavosanguineus e Cortinarius bisporiger. – Micologia e Vegetazione Mediterranea 17: 115–120.
Lavorato, C. & Simonini, G.P. 1997. Boletus flavosanguineus sp. nov. – Rivista di Micologia 40(1): 37–51. (available online as MS Word – document)
Muñoz, J.A. 2005. Boletus s. l. – In: Fungi Europaei. Vol. 1. Pp. 1–951. Edizioni Candusso, Alassio.
Šutara, J., Mikšík, M. & Janda, V. 2009. Hřibovité houby. Čeled’ Boletaceae a rody Gyrodon, Gyroporus, Boletinus a Suillus. Academia, Praha.
Κωνσταντινίδης, Γ. 2009. Μανιτάρια, φωτογραφικός οδηγός μανιταροσυλλέκτη. Αυτοέκδοση, Αθήνα. [Konstantinidis, G. 2009. Mushrooms, a photographic guide for collectors. Published by the author, Athens.]