Xerocomus is a genus of poroid fungi related to Boletus. Many mycologists did not originally recognize the distinction between the two genera and placed Xerocomus taxa in genus Boletus. However, several molecular phylogenetic studies have demonstrated that Xerocomus is a heterogeneous genus of polyphyletic origin,[1] which has resulted in further division of Xerocomus into Xerocomellus and Hemileccinum.[2] The members of the genus Xerocomellus are more closely related to Boletus than true Xerocomus is, which is relatively distantly related to Boletus and more closely related to Phylloporus. Other former Xerocomus species have since been moved to Aureoboletus, Imleria, Hortiboletus and Rheubarbariboletus.[3][4][5]
Ladurner and Simonini published a monograph on Xerocomus in 2003,[6] but this predated the taxonomical revisions based on phylogenetic inferences. In 2008, Hills included 18 species found in Britain, not including some species sometimes treated as Xerocomus, and including Boletus pulverulentus and Boletus impolitus.,[7] currently placed in genera Cyanoboletus and Hemileccinum, respectively. More recent phylogenies have confirmed Xerocomus as monophyletic in its new restricted arrangement.[8]
Most members of Xerocomus are edible, though of mediocre gastronomical value and inferior to the sought-after porcini.
Longitudinally striated or smooth, never bacillate
Bacillate
Hymenophoral trama
Boletoid type with gelatinous lateral strata
Boletoid type with gelatinous lateral strata
Intermediate between boletoid and phylloporoid when fully developed with distinct but weakly gelatinous lateral strata
Phylloporoid type with nongelatinous lateral strata
Pileipellis
Trichoderm, sometimes collapsing, rarely ixotrichoderm or other
Initially trichoderm but collapses with age
Initially palisadoderm, typically encrusted
Initially a trichoderm, never encrusted
Lateral stipe stratum
Frequently gelatinous, 60-90 μM thick, thicker than that of Xerocomellus
Similar to that of Leccinum species, ornamented with stipe scabrousities up to 400-640 μM thick
Frequently not present, reduced to no more than 30-40 μM thick, not gelatinous
Lateral stipe stratum never gelatinous and 80-200 μM thick
References
^ abNuhn ME, Binder M, Taylor AF, Halling RE, Hibbett DS (2013). "Phylogenetic overview of the Boletineae". Fungal Biology. 117 (7–8): 479–511. doi:10.1016/j.funbio.2013.04.008. PMID23931115.
^Klofac W. (2010). "Die Gattung Aureoboletus, ein weltweiter Überblick. Ein Beitrag zu einer monographischen Bearbeitung" [The genus Aureoboletus, a world-wide survey. A contribution to a monographic treatment]. Österreichische Zeitschrift für Pilzkunde (in German). 19: 133–174 (see pp. 142–3).
^Loizides M, Bellanger JM, Assyov B, Moreau PA, Richard F (2019). "Present status and future of boletoid fungi (Boletaceae) on the island of Cyprus: cryptic and threatened diversity unraveled by 10-year study". Fungal Ecology. 41 (13): 65–81. doi:10.1016/j.funeco.2019.03.008.
^ abcHusbands DR, Henkel TW, Bonito G, Vilgalys R, Smith ME (2013). "New species of Xerocomus (Boletales) from the Guiana Shield, with notes on their mycorrhizal status and fruiting occurrence". Mycologia. 105 (2): 422–35. doi:10.3852/12-146. PMID23080024.
^De AB. (2006). "Two new additions to Indian Boletaceae". Journal of Natural History (India). 2 (1): 11–6. ISSN0973-6166.
^Sagar A, Lakhanpal TN (1991). "Fleshy fungi Of N.W. Himalayas XIV. Species of Boletus new to India". Indian Journal of Mycology and Plant Pathology. 21 (3): 262–3. ISSN0303-4097.
^Nilson, S.; Persson, O. (1977). Fungi of Northern Europe 1: Larger Fungi (Excluding Gill-Fungi). Penguin. p. 106. ISBN0-14-063005-8.
^Halling RE, Fechner N, Nuhn M, Osmundson T, Soytong K, Arora D, Binder M, Hibbett D (2015). "Evolutionary relationships of Heimioporus and Boletellus (Boletales), with an emphasis on Australian taxa including new species and new combinations in Aureoboletus, Hemileccinum and Xerocomus". Australian Systematic Botany. 28 (1): 1–22. doi:10.1071/SB14049.
^Šutara, J. (1989). "The delimitation of the genus Leccinum". Ceská Mykologie. 43: 1–12.
^Šutara J. (1991). "Pseudoboletus, a new genus of Boletales". Ceská Mykologie. 45 (1–2): 1–9.
Moncalvo JM, Vilgalys R, Redhead SA, Johnson JE, James TY, Catherine Aime M, Hofstetter V, Verduin SJ, Larsson E, Baroni TJ, Greg Thorn R, Jacobsson S, Clémençon H, Miller OK (June 2002). "One hundred and seventeen clades of euagarics". Mol. Phylogenet. Evol. 23 (3): 357–400. Bibcode:2002MolPE..23..357M. doi:10.1016/S1055-7903(02)00027-1. PMID12099793.