Xerocomus

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]

Xerocomus
Xerocomus subtomentosus
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Boletales
Suborder:	Boletineae
Family:	Boletaceae
Genus:	Xerocomus Quél. (1887)
Type species
Xerocomus subtomentosus (L.) Quél. (1888)

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.

Species

• X. albobrunneus Heinem. & Gooss.-Font. 1951
• X. albotessellatus Heinem. 1964
• X. alliaceus (Beeli) Heinem. 1951
• X. amazonicus Singer 1978
• X. anthracinus M.Zang, M.R.Hu & W.P.Liu 1991
• X. astereicola Imazeki 1952
• X. astraeicolopsis J.Z.Ying & M.Q.Wang 1981
• X. belizensis — Belize[9]
• X. chrysonemus
• X. cyaneibrunnescens — Guyana[10]
• X. ferrugineus
• X. griseo-olivaceus — New Zealand[11]
• X. guidonis
• X. illudens — North America, India and Bangladesh[1][12][13]
• X. lentistipitatus — New Zealand[11]
• X. mcrobbii — New Zealand[11]
• X. nothofagi — New Zealand[11]
• X. olivaceus — Belize[9]
• X. parvogracilis — Guyana[10]
• X. porophyllus — China[14]
• X. potaroensis — Guyana[10]
• X. rufostipitatus — New Zealand[11]
• X. silwoodensis (edibility not known, found in England, Spain, and Italy. Named seventh top species of 2008, International Institute for Species Exploration[15])
• X. squamulosus — New Zealand[11]
• X. subtomentosus (edible and very common, found in Eurasia, North America and Australia )[16][17]
• Xerocomus tenax[18]

Description

Morphological features of xerocomoid boletes[2][19][20]

	Boletus s.str.	Hemileccinum	Xerocomellus	Xerocomus s.str.
Spore Surface	Smooth	Smooth	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

1. Nuhn 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. PMID 23931115.
2. Šutara J. (2008). "Xerocomus s.l. in the light of the present state of knowledge" (PDF). Czech Mycology. 60 (1): 29–62. doi:10.33585/cmy.60104.
3. 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).
4. Vizzini A. (12 June 2014). "Nomenclatural novelties" (PDF). Index Fungorum (147): 1. ISSN 2049-2375.
5. Vizzini A. (26 June 2015). "Nomenclatural novelties" (PDF). Index Fungorum: 1. ISSN 2049-2375.
6. Ladurner H, Simonini G (2003). Xerocomus s.l. Fungi Europaei. 8. Alassio: Edizioni Candusso. ISBN 978-88-901057-2-2.
7. Hills AE. (2008). "The genus Xerocomus: A personal view, with a key to the British species". Field Mycology. 9 (3): 77–96. doi:10.1016/S1468-1641(10)60416-1.
8. 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.
9. Ortiz-Santana B, Lodge DJ, Baroni TJ, Both EE (2007). "Boletes from Belize and the Dominican Republic" (PDF). Fungal Diversity. 27: 247–416 (see p. 379).
10. Husbands 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. PMID 23080024.
11. McNabb RFR. (1968). "The Boletaceae of New Zealand". New Zealand Journal of Botany. 6 (2): 137–76. doi:10.1080/0028825X.1968.10429056.
12. De AB. (2006). "Two new additions to Indian Boletaceae". Journal of Natural History (India). 2 (1): 11–6. ISSN 0973-6166.
13. 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. ISSN 0303-4097.
14. Yan WJ, Li TH, Zhang M, Li T (2013). "Xerocomus porophyllus sp. nov., morphologically intermediate between Phylloporus and Xerocomus". Mycotaxon. 124: 255–62. doi:10.5248/124.255.
15. "Archived copy". Archived from the original on May 28, 2008. Retrieved May 27, 2008.CS1 maint: archived copy as title (link)
16. Arora, D. (1986). Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi (2nd ed.). Berkeley, California: Ten Speed Press. pp. 517–18. ISBN 0-89815-169-4.
17. Nilson, S.; Persson, O. (1977). Fungi of Northern Europe 1: Larger Fungi (Excluding Gill-Fungi). Penguin. p. 106. ISBN 0-14-063005-8.
18. 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.
19. Šutara, J. (1989). "The delimitation of the genus Leccinum". Ceská Mykologie. 43: 1–12.
20. 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. doi:10.1016/S1055-7903(02)00027-1. PMID 12099793.

External links

• The genus Xerocomus
• Xerocomus subtomentosus
• "Xerocomus Quél". Atlas of Living Australia.
• Media related to Xerocomus at Wikimedia Commons