Editing Boletus edulis (section)

==Description==
[[File:Boletus edulis herkkutatti halki.jpg|thumb|alt=Both halves of a thick-stemmed bisected mushroom.|Cross-section showing white flesh, broad stem, and spore tubes on the underside of the cap]]

The [[Pileus (mycology)|cap]] of this mushroom is {{convert|7|–|30|cm|in|frac=2|abbr=on}} broad at maturity. Slightly sticky to touch, it is convex in shape when young and flattens with age. The colour is generally reddish-brown fading to white in areas near the margin, and continues to darken as it matures. The [[Stipe (mycology)|stipe]], or stem, is {{convert|8|–|25|cm|in|frac=2|abbr=on}} in height, and up to {{convert|7|cm|in|frac=2|abbr=on}} thick—rather large in comparison to the cap;<ref name=Kozikowski1996/> it is club-shaped, or bulges out in the middle. It is finely [[wikt:reticulate|reticulate]] on the upper portion, but smooth or irregularly ridged on the lower part. The under surface of the cap is made of thin tubes, the site of [[Basidiospore|spore]] production; they are {{convert|1|to|2|cm|in|frac=4|abbr=on}} deep, and whitish in colour when young, but mature to a greenish-yellow.<ref name=Grund1976/> The angular pores, which do not stain when bruised, are small—roughly 2 to 3 pores per millimetre.<ref name=Tylutki1987II>{{cite book|title=Mushrooms of Idaho and the Pacific Northwest. Vol. 2. Non-gilled Hymenomycetes|author=Tylukti EE. |year=1987 |publisher=The [[University of Idaho Press]] |location=Moscow, Idaho|pages=9–10 |isbn= 0-89301-097-9}}</ref> In youth, the pores are white and appear as if stuffed with cotton (which are actually [[mycelia]]); as they age, they change colour to yellow and later to brown. The spore print is olive brown. The flesh of the fruit body is white, thick and firm when young, but becomes somewhat spongy with age. When bruised or cut, it either does not change colour, or turns a very light brown or light red.<ref name=Wang1995/> Fully mature specimens can weigh about {{convert|1|kg|lboz|abbr=on}}; a huge specimen collected on the [[Isle of Skye]], Scotland, in 1995 bore a cap of {{convert|42|cm|in|frac=2|abbr=on}}, with a stipe {{convert|18|cm|in|frac=2|abbr=on}} in height and {{convert|14|cm|in|frac=2|abbr=on}} wide, and weighed {{convert|3.2|kg|lboz|abbr=on}}.<ref name=Kozikowski1996>{{cite journal|author=Kozikowski GR.|year=1996 |title=Foray Report from Skye |journal=Mycologist |volume=10 |pages=183–84 |doi=10.1016/S0269-915X(96)80022-X |issue=4}}</ref> A similarly sized specimen found in Poland in 2013 made international news.<ref>{{Cite news | url=https://www.bbc.co.uk/news/world-europe-24292021 | title=Giant mushroom found in Poland| work=BBC News}}</ref>
{{multiple image
| align = left
| image1 = Boletus edulis (7).jpg
| width1 = 72
| alt1 = A brown-capped mushroom lying flat on the grass with a white or light-brown coloured stem that gradually gets thicker, so as to roughly resemble the shape of a club.
| caption1 = 
| image2 = Boletus edulis JPG9.jpg
| width2 = 128
| alt2 = A brown-capped mushroom with a short, stout stem that is thickest in the middle, and whose thickness approaches the width of the cap it supports.
| caption2 = 
| footer = Stem shape can range from club-shaped to centrally bulbous
}}
''Boletus edulis'' is considered one of the safest wild mushrooms to pick for the table, as few poisonous species closely resemble it, and those that do may be easily distinguished by careful examination.<ref name = "Carluccio03"/> The most similar poisonous mushroom may be the devil's bolete (''[[Rubroboletus satanas]]''), which has a similar shape, but has a red stem and stains blue on bruising.<ref name="Carluccio03" /> It is often confused with the very bitter and unpalatable ''[[Tylopilus felleus]]'', but can be distinguished by the reticulation on the stalk; in porcini, it is a whitish, net-like pattern on a brownish stalk, whereas it is a dark pattern on white in the latter. Porcini have whitish pores while the other has pink. If in doubt, tasting a tiny bit of flesh will yield a bitter taste.<ref name = "Carluccio03"/> It can also resemble the "bolete-like" ''[[Gyroporus castaneus]]'', which is generally smaller, and has a browner stem. ''[[Boletus huronensis]],'' an uncommon mushroom of northeastern North America, is another recognized look-alike known to cause severe [[gastrointestinal disorder]]s.<ref>{{cite web|url=https://namyco.org/boletus_huronensis.php|title=''Boletus huronensis'': Comments on its toxicity with diagnostic images of its field characteristics and staining reactions|author=Bill Bakaitis|publisher=North American Mycological Association|date=2019}}</ref>

The [[basidiospore|spores]] are elliptical to spindle-shaped, with dimensions of 12–17 by 5–7&nbsp;[[micrometre|μm]]. The [[basidia]], the spore-bearing cells, are produced in a layer lining the tubes, and arrange themselves so their ends are facing the center of the tube; this layer of cells is known technically as a [[hymenium]]. The basidia are thin-walled, mostly attached to four spores, and measure 25–30 by 8–10&nbsp;μm. Another cell type present in the hymenium is the cystidia, larger sterile cells that protrude beyond the basidia into the [[lumen (anatomy)|lumen]] of the hymenium, and act as air traps, regulating humidity.<ref>{{cite book|vauthors=Alexopoulos CJ, Mims CW, Blackwell M | title=Introductory Mycology | year=1996 | publisher=John Wiley and Sons |location=New York City|page=495 | isbn=0-471-52229-5}}</ref> ''B.&nbsp;edulis'' has pleurocystidia (cystidia located on the face of a pore) that are thin-walled, roughly spindle-shaped to [[ventricose]], and measure 30–45 by 7–10&nbsp;μm; the "stuffed" feature of the hymenium is caused by cheilocystidia—cells found on the edges of the pores.<ref name=Grund1976>{{cite book |title=Nova Scotian Boletes |vauthors=Grund DW, Harrison AK |year=1976 |publisher=J. Cramer |location=Lehre, Germany |isbn=3-7682-1062-6|pages=73–75}}</ref> The [[hypha]]e of ''B.&nbsp;edulis'' do not have [[clamp connection]]s.<ref name=Tylutki1987II/>

===Related species===
{{multiple image
| align = right
| image1 = Boletus edulis var. grandedulis 27911.jpg
| width1 = 100
| alt1 = A mushroom with an orange-brown cap and a yellowish underside that somewhat resembles a sponge. The light-yellow stem is about half the thickness of the caps diameter. This mushroom is growing on the ground, surrounded by twigs, leaves, log and other forest floor debris.
| caption1 = ''B. edulis'' var. ''grandedulis''
| image2 = Boletus regineus 28082.jpg
| width2 = 100
| alt2 = A mushroom with a reddish-brown cap that is curled upwards to reveal a cream-coloured porous underside that somewhat resembles a sponge. The thick stipe has a pinkish hue, and its thickness is a little less than half of the cap's diameter. The mushroom has been pulled from the ground and the end of its stipe is a whitish colour caused by hyphal tufts, and is embedded with dirt and other small twigs.
| caption2 = ''B. regineus''
| footer = 
}}
Several similar brownish-coloured species are sometimes considered subspecies or forms of this mushroom. In Europe, in addition to ''B.&nbsp;edulis'' (or ''cèpe de Bordeaux''), the most popular are:
*''Cèpe bronzé'' ("dark cep"; ''[[Boletus aereus]]''), much rarer than ''B.&nbsp;edulis'', is more highly regarded by gourmets, and consequently more expensive. Usually smaller than ''B.&nbsp;edulis'', it is also distinctively darker in colour.<ref name = "Carluccio03"/> It is especially suited to drying.<ref name=Zeitl76/>
*''Cèpe des pins'' ("pine tree cep"; ''[[Boletus pinophilus]]'' or ''Boletus pinicola'') grows among pine trees. Rarer than ''B.&nbsp;edulis'', it is less appreciated by gourmets than the two other kinds of porcini, but remains a mushroom rated above most others.<ref name=Zeitl76/>
*''Cèpe d'été'' ("summer cep"; ''[[Boletus reticulatus]]''), also less common and found earlier.<ref name = "Carluccio03"/>

[[Molecular phylogenetic]] analyses have proven these three are all distinctive and separate species;<ref>{{cite journal |vauthors=Vizzini A, Mello A, Ghignone S, Sechi C, Ruiu P, Bonfante P |year=2008 |title=''Boletus edulis'' complex: from phylogenetic relationships to specific primers |journal=Pagine di Micologia |issue=30 |pages=49–52 |issn=1122-8911}}</ref> other taxa formerly believed to be unique species or subspecies, such as ''B.&nbsp;betulicola'', ''B.&nbsp;chippewaensis'', ''B.&nbsp;persoonii'', ''B.&nbsp;quercicola'' and ''B.&nbsp;venturii'', are now known to be part of a ''B.&nbsp;edulis'' [[species complex]] with a wide [[morphology (biology)|morphological]], ecological and geographic range,<ref>{{cite journal |author1=Beugelsdijk DCM |author2=van der Linde S |author3=Zuccarello GC |author4=den Bakker |author5=Draisma SGA |author6=Noordeloos ME. |year=2008 |title= A phylogenetic study of ''Boletus'' section ''Boletus'' in Europe |journal=Persoonia |pmid= 20467482 |volume=20 |issue=1 |pmc= 2865352 |pages=1–7|doi=10.3767/003158508X283692 }}</ref><ref name=dent10>{{cite journal|vauthors=Dentinger BT, Ammirati JF, Both EE, Desjardin DE, Halling RE, Henkel TW, Moreau PA, Nagasawa E, Soytong K, Taylor AF, Watling R, Moncalvo JM, McLaughlin DJ |title=Molecular phylogenetics of porcini mushrooms (''Boletus'' section ''Boletus'') |journal=Molecular Phylogenetics and Evolution |volume=57 |year=2010 |pages=1276–1292 |url=http://static.msi.umn.edu/rreports/2010/211.pdf |doi=10.1016/j.ympev.2010.10.004 |issue=3 |pmid=20970511 |archive-url=https://web.archive.org/web/20130523094609/http://static.msi.umn.edu/rreports/2010/211.pdf |archive-date=2013-05-23 }}</ref> and that the genetic variability in this complex is low.<ref>{{cite journal|vauthors=Beugelsdijk DC, van der Linde S, Zuccarello GC, den Bakker HC, Draisma SG, Noordeloos ME |year=2008|title=A phylogenetic study of ''Boletus'' section ''Boletus'' in Europe|journal=Persoonia|volume=20|pages=1–7|pmid=20467482|doi=10.3767/003158508X283692|pmc=2865352}}</ref> Similar molecular technology has been developed to rapidly and accurately identify ''B.&nbsp;edulis'' and other commercially important fungi.<ref>{{cite journal |vauthors=Mello A, Ghignone S, Vizzini A, Sechi C, Ruiu P, Bonfante P |year=2006 |title=ITS primers for the identification of marketable boletes |journal=Journal of Biotechnology |volume=121 |issue=3 |pages=318–29 |doi=10.1016/j.jbiotec.2005.08.022 |pmid=16213623}}</ref><ref>{{cite journal |vauthors=Lian B, Zang JP, Hou WG, Yuan S, Smith DL |year=2008 |title=PCR-based sensitive detection of the edible fungus ''Boletus edulis'' from rDNA ITS sequences |journal=Electronic Journal of Biotechnology |volume=11 |issue=3 |pages=1–8 |doi=10.2225/vol11-issue3-fulltext-4 |doi-broken-date=2024-11-10 |issn=0717-3458|url=http://www.bioline.org.br/pdf?ej08040 |hdl=1807/48975 |hdl-access=free }}</ref>

Three divergent lineages found in Yunnan province in China that are commonly marketed and sold as ''B. edulis'' (and are actually more closely related to ''B. aereus'') were described in 2013 as ''[[Boletus bainiugan|B. bainiugan]]'', ''[[Boletus meiweiniuganjun|B. meiweiniuganjun]]'' and ''[[Boletus shiyong|B. shiyong]]''.<ref name="Dentinger 2013">{{cite journal|author=Dentinger B|date=12 October 2013|title=Nomenclatural novelties|journal=Index Fungorum|issue=29|page=1|issn=2049-2375|url=http://www.indexfungorum.org/Publications/Index%20Fungorum%20no.29.pdf}}</ref><ref name="Dentinger 2014">{{cite journal|vauthors=Dentinger B, Suz LM |date=2014|title=What's for dinner? Undescribed species of porcini in a commercial packet|journal=PeerJ |volume=2|issue=2:e570|pages=e570|doi=10.7717/peerj.570|pmid=25279259|pmc=4179395 |doi-access=free }}</ref> The classification has since been updated and expanded. All lineages are still members of ''Boletus'' sect. ''Boletus'', the sensu sticto "porcini clade" of the genus.<ref name=Cui2016>{{cite journal |last1=Cui |first1=Yang-Yang |last2=Feng |first2=Bang |last3=Wu |first3=Gang |last4=Xu |first4=Jianping |last5=Yang |first5=Zhu L. |title=Porcini mushrooms (Boletus sect. Boletus) from China |journal=Fungal Diversity |date=November 2016 |volume=81 |issue=1 |pages=189–212 |doi=10.1007/s13225-015-0336-7 |s2cid=12866685 |url=http://groups.kib.cas.cn/klpb/yzl/tnh_fblw/201509/P020150928547013572278.pdf}}</ref>

[[File:Boletus rex-veris 42967.jpg|thumb|left|''B. rex-veris''|alt=A group of three mushrooms with reddish-brown caps, bright yellow porous undersides, and thick white stipes. They are growing on the ground in soil covered with pine needles.]]
Western North America has several species closely related to ''B.&nbsp;edulis''. The white king bolete (''[[Boletus barrowsii]]''), found in parts of [[Colorado]], [[New Mexico]], [[Arizona]], and California (and possibly elsewhere), is named after its discoverer Chuck Barrows.<ref>{{cite web|url=http://botit.botany.wisc.edu/Toms_fungi/aug2004.html|access-date=2008-09-23|title=''Boletus barrowsii'', Chuck Barrows' bolete|author=Volk T.|date=August 2004|work=Tom Volk's Fungus of the Month|publisher=Department of Biology, University of Wisconsin-La Crosse|archive-url=https://web.archive.org/web/20081003220326/http://botit.botany.wisc.edu/toms_fungi/aug2004.html <!--Added by H3llBot-->|archive-date=2008-10-03}}</ref> It is lighter in colour than ''B.&nbsp;edulis'', having a cream-coloured cap with pink tones;<ref name=Miller2006>{{cite book |vauthors=Miller HR, Miller OK |title=North American Mushrooms: a Field Guide to Edible and Inedible Fungi |publisher=Falcon Guide |location=Guilford, Conn |year=2006 |page=392 |isbn=0-7627-3109-5 }}</ref> often mycorrhizal with [[Ponderosa pine]], it tends to grow in areas where there is less rainfall. Some find its flavour as good as if not better than ''B.&nbsp;edulis''.<ref name=Evenson>{{cite book |title=Mushrooms of Colorado and the Southern Rocky Mountains |author=Evenson VS. |year=1997 |publisher=Westcliffe Publishers |location= Boulder, Colorado|isbn=978-1-56579-192-3 |page=157|url=https://books.google.com/books?id=EAeDeyqZLq0C&q=boletus%20edulis&pg=PA157|access-date=2009-10-20}}</ref> The California king bolete (''Boletus edulis var. grandedulis'') can reach massive proportions, and is distinguished from ''B.&nbsp;edulis'' by a mature pore surface that is brown to slightly reddish. The cap colour appears to be affected by the amount of light received during its development, and may range from white in young specimens grown under thick [[forest canopy|canopy]], to dark-brown, red-brown or yellow brown in those specimens receiving more light.<ref name=eb1>{{cite journal |author=Arora D. |year=2008 |title=California porcini: three new taxa, observations on their harvest, and the tragedy of no commons |journal=Economic Botany |volume=62 |issue=3 |pages=356–75 |url=http://www.davidarora.com/uploads/arora_california_porcini.pdf |doi=10.1007/s12231-008-9050-7 |s2cid=23176365 |access-date=2009-11-04 |archive-date=2012-03-12 |archive-url=https://web.archive.org/web/20120312213054/http://www.davidarora.com/uploads/arora_california_porcini.pdf }}</ref> The queen bolete (''[[Boletus regineus]]''), formerly considered a variety of ''B.&nbsp;aereus'', is also a choice edible. It is generally smaller than ''B.&nbsp;edulis'', and unlike that species, is typically found in [[mixed forest]]s.<ref name="urlCalifornia Fungi: Boletus regineus">{{cite web |url=http://www.mykoweb.com/CAF/species/Boletus_regineus.html |title=California Fungi: ''Boletus regineus'' |vauthors=Wood M, Stevens F |publisher=MykoWeb |access-date=2009-11-02}}</ref> The spring king bolete (''[[Boletus rex-veris]]''), formerly considered a variety of ''B.&nbsp;edulis'' or ''B.&nbsp;pinophilus'', is found throughout western North America. In contrast to ''B.&nbsp;edulis'', ''B.&nbsp;rex-veris'' tends to fruit in clusters, and, as its common name suggests, appears in the spring.<ref name="urlCalifornia Fungi: Boletus rex-veris">{{cite web |url=http://www.mykoweb.com/CAF/species/Boletus_rex-veris.html |title=California Fungi: ''Boletus rex-veris'' |vauthors=Wood M, Stevens F |publisher= MykoWeb|access-date=2009-11-03}}</ref> ''[[Boletus fibrillosus|B.&nbsp;fibrillosus]]'' is edible but considered inferior in taste.<ref>{{cite book|last1=Trudell|first1=Steve|url=https://books.google.com/books?id=WevHvt6Tr8kC|title=Mushrooms of the Pacific Northwest|last2=Ammirati|first2=Joe|publisher=Timber Press|year=2009|isbn=978-0-88192-935-5|series=Timber Press Field Guides|location=Portland, OR|page=217}}</ref>