Boletus L.
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 appendiculatus Schaeff. : Fr.
Description
Cap up to 20 cm, convex to flat-convex, initially dry, finely felty, very soon smooth or finely cracked, brown to dark brown, rarely pale brown, not blueing when bruised. Stipe clavate or cylindrical, often tapering and rooting, lemon yellow to yellow, sometimes discolouring in places to pale yellowish, sometimes with pinkish or reddish zone at the middle, at least in the upper half but most often entirely covered with fine network, stipe surface blueing when bruised. Flesh yellowish, in the stipe base pinkish or brownish pink, blueing predominantly in the cap when exposed to air. Tubes initially lemon yellow, then yellow, finally yellow with olivaceous tint, blueing when exposed to air. Smell not distinctive. Taste not distinctive. Spores 9–15 × 3.5–5.5 μm, ratio 2–3.5. Pileipellis (the cap cuticle) trichodermium of interwoven septate hyphae. Cells of the hyphae cylindrical, finely incrusted. Chemical reactions: the hyphae of the flesh in the stipe base inamyloid with Melzer’s solution.
Habitat. Sheltered broadleaf forests, mycorrhizal with oaks (Quercus), beech (Fagus) or sweet chestnut (Castanea sativa), often on calcareous soils.
Distribution. In Europe widespread, likely more common in south.
Similarity. Similar to Boletus subappendiculatus, which has usually paler cap, whitish, not blueing flesh, slightly different spore ratio, and grows under conifers.
Photographs
Fruitbodies of Boletus appendiculatus. (photo M. Mikšík)
Fruitbodies of Boletus appendiculatus in different stages of development. (photo Y. Sytillidis)
Fruitbody of Boletus appendiculatus. (photo B. Assyov)
Boletus appendiculatus. Note the yellow pores, bruising blue. (photo B. Assyov)
Boletus appendiculatus. Detail of network on the stipe. (photo B. Assyov)
Schaeffer's illustration accompanying the original description of Boletus appendiculatus. Figures numbers redrawn in contemporary font to facilitate reading.
Important literature
Alessio, C.L. 1985. Boletus Dill. ex L. (sensu lato). – In: Fungi Europaei. Vol. 2. Pp. 1–705. Libreria editrice Biella Giovanna, Saronno.
Assyov, B. (2012). Revision of Boletus section Appendiculati (Boletaceae) in Bulgaria with a key to the Balkan species. – Turkish Journal of Botany 36: 408–419. (available online)
Breitenbach J. & Kränzlin F. 1991. Pilze der Schweiz. Bd. 3(1). Röhrlinge und Blätterpilze. Verlag Mykologia, Luzern.
Engel, H., Krieglsteiner, G., Dermek, A. & Watling, R. 1983. Dickröhrlinge. Die Gattung Boletus in Europa. Verlag Heinz Engel, Weidhausen b. Coburg.
Estadès, A. & Lannoy, G. 2004. Les bolets européens. – Bulletin Mycologique et Botanique Dauphiné-Savoie 44(3): 3–79.
Galli, R. 1998. I Boleti. Atlante pratico-monographico per la determinazione dei boleti. Edinatura, Milano.
Hansen, L. & Knudsen, H. 1992. Nordic Macromycetes. Vol. 2. Polyporales, Boletales, Agaricales, Russulales. Nordsvamp, Copenhagen.
Knudsen, H. & Vesterholt, J. [eds.]. 2008. Funga Nordica. Nordsvamp, Kopenhagen.
Lannoy, G. & Estadès, A. 2001. Les Bolets. Flore mycologique d’Europe. Documents Mycologiques Mémoire Hors série no. 6. Pp. 1–163. Association d’Écologie et de Mycologie, Lille.
Marques, G. & Muñoz, J.A. 2006. Révision des espèces européennes du genre Boletus section Appendiculati. Étude sur la base de caracteres morphologique et d’analyse des polymorphismes des fragments de restriction (PCR-RFLP). – Bulletin Trimestriel de la Société Mycologique de France 122: 353–366.
Muñoz, J.A. 2005. Boletus s. l. – In: Fungi Europaei. Vol. 1. Pp. 1–951. Edizioni Candusso, Alassio.
Pilát, A. & Dermek, A. 1974. Hríbovité huby. Československé hríbovité a sliziakovité huby (Boletaceae – Gomphidiaceae). Veda, Bratislava.
Singer, R. 1967. Die Röhrlinge. II. Die Boletoideae und Strobilomycetaceae. – In: Die Pilze Mitteleuropas. Vol. 6. Pp. 1–151. Julius Klinkhardt Verlag, Bad Heilbrunn.
Šutara, J., Mikšík, M. & Janda, V. 2009. Hřibovité houby. Čeled’ Boletaceae a rody Gyrodon, Gyroporus, Boletinus a Suillus. Academia, Praha.
Watling, R. 1970. Boletaceae, Gomphidiaceae, Paxillaceae. – In: Henderson, D.M., Orton, P.D. & Watling, R. [eds]. British fungus flora. Agarics and Boleti. Vol. 1. Royal Botanic Garden, Edinburgh.
Watling, R. & Hills, A.E. 2005. Boletes and their allies (revised and enlarged edition). – In: Henderson, D.M., Orton, P.D. & Watling, R. [eds]. British Fungus Flora. Agarics and boleti. Vol. 1. Royal Botanic Garden, Edinburgh.