Boletaceae
The Boletaceae are a family of mushroom-forming fungi, primarily characterised by small pores on the spore-bearing hymenial surface, instead of gills as are found in most agarics. Nearly as widely distributed as the agarics, the family is renowned for hosting some prime edible species highly sought after by mushroom hunters worldwide, such as the cep or king bolete. A number of rare or threatened species are also present in the family, that have become the focus of increasing conservation concerns. As a whole, the typical members of the family are commonly known as boletes.
Boletes are a group of mushrooms reasonably safe for human consumption, as none of them are known to be deadly to adults. Edible bolete species are especially suitable for novice collectors, since they pose little danger of being confused with deadly poisonous mushrooms, such as deadly Amanita species which bear gills instead of pores in their hymenial surface. Some boletes are toxic and may cause gastrointestinal poisoning if consumed, but these are unlikely to be confused with popular edible species in the family.
The family has been the subject of extensive systematic revisions in recent years, as some of the early established genera, have revealed to be highly polyphyletic, and the original number of genera within the family had been underestimated. As a result, several new species and genera have been described from Asia, Europe and North America, while many existing species have been transferred to different genera, in concordance with phylogenetic results.
Description
Most species of Boletaceae produce large, fleshy mushrooms, with a more or less central stipe. The fruit bodies typically have tubular hymenophores, although a small number of species are lamellate.The spore deposit colours are commonly olivaceous, yellowish, brownish, or vinaceous, and when viewed under the microscope spores are usually fusiform or subfusiform. In many species, parts of the fruit body will turn blue, red, or black when bruised or exposed to the air, as a result of the oxidation of pulvinic acid derivatives, like variegatic, xerocomic, and atrotomentinic acids.
Taxonomy
Boletaceae were first described by the French botanist François Fulgis Chevallier in 1826, as a family distinct from Agaricaceae. Five genera were initially included in Chevallier's circumscription: Boletus, Cladoporus, Physisporus, Polyporus, and Fistulina. However, all of the original genera except Boletus have since been transferred to different families, and several new Boletaceae genera have been described.Genera
, in the 4th edition of his Agaricales in Modern Taxonomy, included 26 genera and 415 species in Boletaceae. In the Dictionary of the Fungi, 35 Boletaceae genera were recognised, which collectively contained 787 species. Molecular phylogenetic studies in the 2000s have revised the concept of the family; in a highly cited 2006 publication, Manfred Binder and David Hibbett recognised 38 genera within the family, many of which had remained at the time undescribed. The number of Boletaceae genera increased significantly in the following years, as some of the early-established genera, further revealed to be highly polyphyletic. In the comprehensive work of Wu and colleagues, seven major clades at subfamily level and 59 generic lineages were uncovered, including four new subfamilies and 22 potential new genera. To formally name the generic lineages unravelled by molecular phylogenies, several new genera have since been described from Asia, Europe and North America including, among others, Baorangia, Butyriboletus, Cacaoporus, Caloboletus, Exsudoporus, Imperator and Rubroboletus.Some characters traditionally emphasised in morphology-based taxonomy, such as basidiospore ornamentation and "stuffed" pore morphology, revealed to be incongruent with molecular taxonomy, suggesting that certain traits evolved more than once within the family.
| Genus | Authority | Year | No. of species | Distribution |
| Afroboletus | Pegler & T.W.K.Young | 1981 | 7 | tropical Africa |
| Alessioporus | Gelardi, Vizzini & Simonini | 2014 | 1 | southern Europe |
| Aureoboletus | Pouzar | 1957 | 17 | widespread |
| Australopilus | Halling & Fechner | 2012 | 1 | Australia |
| Austroboletus | Wolfe | 1980 | America, Australasia | |
| Baorangia | G. Wu & Zhu L. Yang | 2015 | East Asia, North America | |
| Boletellus | Murrill | 1909 | widespread | |
| Boletochaete | Singer | 1944 | 3 | Africa, Southeast Asia |
| Boletus | Fr. | 1821 | widespread | |
| Borofutus | Hosen & Zhu L.Yang | 2012 | 1 | Bangladesh |
| Bothia | Halling, T.J.Baroni, & Binder | 2007 | 1 | North America |
| Buchwaldoboletus | Pilát | 1962 | 3 | Europe, Australia |
| Butyriboletus | D.Arora & J.L.Frank | 2014 | 18 | widespread |
| Cacaoporus | Raspé & Vadthanarat | 2019 | 2 | Thailand |
| Caloboletus | Vizzini | 2014 | 13 | widespread |
| Chalciporus | Bataille | 1908 | 25 | widespread |
| Chamonixia | Rolland | 1899 | 8 | widespread |
| Corneroboletus | N.K.Zeng & Zhu L.Yang | 2012 | 1 | Singapore, Malaysia, tropical China |
| Crocinoboletus | N.K. Zeng, Zhu L. Yang & G. Wu | 2015 | 2 | East Asia, South Asia |
| Cyanoboletus | Gelardi, Vizzini & Simonini | 2014 | 3 | widespread |
| Durianella | A.W.Wilson & Manfr.Binder | 2008 | 1 | Malaysia, Borneo |
| Erythrophylloporus | Raspé, Vadthanarat & Lumyong | 2019 | 3 | China, Thailand |
| Exsudoporus | Vizzini, Simonini & Gelardi | 2014 | 3 | North America, Europe |
| Fistulinella | Henn. | 1901 | 15 | pantropical |
| Gastroboletus | Lohwag | 1962 | 13 | widespread |
| Gastroleccinum | Thiers | 1989 | 1 | North America |
| Harrya | Halling, Nuhn & Osmundson | 2012 | 2 | Asia, North America, Central America |
| Heimioporus | E.Horak | 2004 | widespread | |
| Heliogaster | Orihara & Iwase | 2010 | 1 | Japan |
| Hemileccinum | Šutara | 2008 | 3 | Europe, North America |
| Hortiboletus | Simonini, Vizzini & Gelardi | 2015 | 4 | Europe, North America |
| Imleria | Vizzini | 2014 | 4 | Europe, Asia, North America |
| Imperator | Assyov et al. | 2015 | 3 | Europe, West Asia |
| Kaziboletus | Iqbal Hosen, Zhu L.Yang | 2021 | 1 | South Asia |
| Lanmaoa | G. Wu, Zhu L. Yang, Halling | 2015 | >5 | East Asia, North America |
| Leccinellum | Bresinsky & Manfr. Binder | 2003 | 10 | widespread |
| Leccinum | Gray | 1821 | widespread | |
| Mucilopilus | Wolfe | 1979 | 4 | North America, New Zealand |
| Mycoamaranthus | Castellano, Trappe & Malajczuk | 1992 | 3 | Australasia, Africa, Southeast Asia |
| Neoboletus | Gelardi et al. | 2014 | 9 | Europe, Asia |
| Nigroboletus | Gelardi, Vizzini, E. Horak, T.H. Li & Ming Zhang | 2015 | 1 | China |
| Octaviania | Vittad. | 1831 | 15 | widespread |
| Parvixerocomus | G. Wu & Zhu L. Yang, | 2015 | 2 | East Asia |
| Paxillogaster | E.Horak | 1966 | 1 | South America |
| Phylloboletellus | Singer | 1952 | 1 | Central and South America |
| Phyllobolites | Singer | 1942 | 1 | South America |
| Phylloporus | Quel. | 1888 | cosmopolitan | |
| Pseudoaustroboletus | Yan C. Li & Zhu L. Yang | 2014 | 1 | East Asia, South Asia |
| Pseudoboletus | Šutara | 1991 | 2 | north temperate regions |
| Pulchroboletus | Vizzini, Simonini & Gelardi | 2014 | 1 | southern Europe |
| Pulveroboletus | Murrill | 1909 | 25 | cosmopolitan |
| Retiboletus | Manfr. Binder & Bresinsky | 2002 | 5 | north temperate regions |
| Rheubarbariboletus | Vizzini, Simonini & Gelardi | 2015 | 2 | Europe |
| Rhodactina | Pegler & T.W.K.Young | 1989 | 2 | India, Thailand |
| Rossbeevera | T.Lebel & Orihara | 2011 | 9 | Asia, Australia |
| Royoungia | Castellano, Trappe & Malajczuk | 1992 | 1 | Australia |
| Rubroboletus | Kuan Zhao & Zhu L.Yang | 2014 | 8 | Widespread |
| Rugiboletus | G. Wu & Zhu L. Yang | 2015 | 2 | East Asia |
| Setogyroporus | Heinem. & Rammeloo | 1999 | 1 | tropical Africa |
| Singerocomus | T.W.Henkel & M.E.Sm. | 2016 | 3 | ?? |
| Singeromyces | M.M.Moser | 1966 | 1 | Argentina |
| Sinoboletus | M.Zang | 1992 | 10 | China |
| Sirindhornea | Lueangjaroenkit et al. | 2025 | 1 | Thailand |
| Solioccasus | Trappe, Osmundson, Manfr.Binder, Castellano & Halling | 2013 | 1 | Australasia |
| Spongiforma | Desjardin, Manf. Binder, Roekring & Flegel | 2009 | 2 | Thailand, Malaysia |
| Strobilomyces | Berk. | 1851 | cosmopolitan | |
| Suillellus | Murrill | 1909 | 11 | North America, Europe |
| Sutorius | Halling, Nuhn & Fechner | 2012 | 3 | North America, Costa Rica, Africa, S.E. Asia, Australia |
| Tubosaeta | E.Horak | 1967 | 5 | Africa, Asia |
| Tylopilus | P.Karst | 1881 | widespread | |
| Veloporphyrellus | L.D.Gómez & Singer | 1984 | 1 | Central America |
| Wakefieldia | Corner & Hawker | 1952 | 2 | Asia, Europe |
| Xanthoconium | Singer | 1944 | 7 | cosmopolitan |
| Xerocomellus | Šutara | 2008 | 24 | North and South America, Europe |
| Xerocomus | Quel | 1887 | >20 | widespread |
| Zangia | Yan C.Li & Zhu L.Yang | 2011 | 6 | China |
Note that the phylogenetic and taxonomic position of many taxa currently remaining in genus Boletus has not yet been clarified. The number of species in this genus will therefore significantly reduce in the following years, as more taxa will be transferred to different genera, or found to be synonyms.
Many other genera formerly part of this family have been moved into other, smaller families, as work with molecular phylogeny shows that they are more distantly related, even if morphologically similar. Representative of this adjustment, is the move of the slimy-capped genus Suillus to the family Suillaceae.