Editing Armillaria (section)

== Taxonomy ==
The name ''Armillaria'' was defined in 1821 by [[Elias Magnus Fries]], but at that time most gilled mushrooms were considered to belong to genus ''Agaricus'' and ''Armillaria'' was only a subgenus (a&nbsp;"tribe"). In 1857, Friedrich Staude established the independent genus.<ref name="IF_Armillaria">{{cite web |url=http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=17098 |title=the ''Armillaria'' page |work=Species Fungorum |publisher=Royal Botanic Gardens Kew |access-date=2020-09-05 }}</ref>

''Armillaria'' species morphologically similar to ''A. mallea'' were not effectively distinguished until the development of "biological species" defined as intersterile groups by [[Veikko Hintikka]] in 1973.<ref name=Hintikka1973>{{cite journal |author=Hintikka V |year=1973 |title=A note on the polarity of ''Armillaria mellea'' |journal=Karstenia |volume=13 |pages=32–39|doi=10.29203/ka.1973.80 |doi-access=free }}</ref> Using a similar technique, [[Kari Korhonen (biologist)|Kari Korhonen]] showed in 1978 that the European ''Armillaria mellea'' [[species complex]] could be separated into five reproductively isolated species, which he named "European Biological Species" (EBS) A through E.<ref name=Korhonen1978>{{cite journal |author=Korhonen K |year=1978 |title=Interfertility and clonal size in the ''Armillaria mellea'' complex |journal=Karstenia |volume=18 |issue=2 |pages=31–42|doi=10.29203/ka.1978.135 |doi-access=free }}</ref> About the same time, the North American ''A.&nbsp;mellea'' was shown to be ten different species (North American Biological Species, or NABS&nbsp;I through X).<ref name=Anderson1979>{{cite journal |vauthors=Anderson JB, Ullrich RC |year=1979 |title=Biological species of ''Armillaria'' in North America |journal=Mycologia |volume=71 |issue=2 |pages=401–14 |jstor=3759160 |doi=10.2307/3759160 }}</ref>

{|class=wikitable
|+Intersterile biological species of ''Armillaria'' defined in Europe and North America
|-
! Code !! Taxonomic treatment !! Compatibility !! Known range
|-
| EBS&nbsp;A || Armillaria borealis {{au|Marxmüller & Korhonen (1982)}}<ref>{{cite web |title=Species acepted in Armillaria |url=https://botit.botany.wisc.edu/toms_fungi/armnames.html |website=botit.botany.wisc.edu}}</ref> || || Finland<ref name=Anderson1980>{{cite journal |vauthors=Anderson JB, Korhonen K, Ullrich RC |year=1980 |title=Relationships between European and North American biological species of ''Armillaria mellea'' |journal=Experimental Mycology |volume=4 |issue=1 |pages=78–86 |doi=10.1016/0147-5975(80)90053-5 }}</ref>
|-
| EBS&nbsp;B || ''Armillaria cepistipes'' {{au|Velen. (1920)}}<ref name="Banik">{{cite journal |last1=Banik |first1=Mark T. |last2=Burdsall |first2=Harold H. |title=Assessment of Compatibility among Armillaria cepistipes, A. sinapina, and North American Biological Species X and XI, Using Culture Morphology and Molecular Biology |journal=Mycologia |date=September 1998 |volume=90 |issue=5 |pages=798 |doi=10.2307/3761321}}</ref> || NABS&nbsp;III ({{abbr|part|partial}} + {{abbr|rg|reduced growth}}), NABS&nbsp;IV (part) || Finland, Germany<ref name=Anderson1980/>
|-
| EBS&nbsp;C || ''Armillaria ostoyae'' {{au|(Romagn.) Herink}} || NABS&nbsp;I (part) || Finland<ref name=Anderson1980/>
|-
| EBS&nbsp;D || ''Armillaria mellea'' {{au|(Vahl ex Fr.) Karst}} || NABS&nbsp;VIII (part + rg) || Finland<ref name=Anderson1980/>
|-
| EBS&nbsp;E  || ''Armillaria gallica'' {{au|(Marxmüller & Romagn.)}} || NABS&nbsp;III (part + rg) || France
|-
| NABS&nbsp;I || ''Armillaria ostoyae'' {{au|(Romagn.) Herink}} || EBS&nbsp;C (part)<ref name=Anderson1980/> || Vermont,<ref name=Anderson1980/> British Columbia, Prairie Provinces (both [[Taiga|boreal]] and [[Montane ecology|subalpine regions]]), Ontario, Quebec.<ref name="mall1"/>
|-
| NABS&nbsp;II || ''Armillaria gemina'' {{au|Bérubé & Dessureault}} || || Vermont,<ref name=Anderson1980/> Quebec.<ref name="mall1"/>
|-
| NABS&nbsp;III || ''Armillaria calvescens'' {{au|Bérubé & Dessureault}} || EBS&nbsp;B and E (part + rg)<ref name=Anderson1980/> || Vermont,<ref name=Anderson1980/> [[Prairie Provinces]], [[Ontario]], [[Quebec]].<ref name="mall1"/>
|-
| NABS&nbsp;IV || || EBS&nbsp;B (part),<ref name=Anderson1980/> NABS&nbsp;V (very low?)<ref name="Banik"/> || Vermont<ref name=Anderson1980/>
|-
| NABS&nbsp;V || ''Armillaria sinapina'' {{au|Bérubé & Dessureault}} || EBS B (5.5%)<ref name="Banik"/> || [[New York (state)]],<ref name=Anderson1980/> British Columbia, Prairie Provinces, Ontario, Quebec.<ref name="mall1"/>
|-
| NABS&nbsp;VI || ''Armillaria mellea'' {{au|(Vahl.:Fries) Kummer}}<ref name="mall2">Mallett, K. I. (1992). "''Armillaria'' root rot in the Canadian Prairie Provinces". Forestry Canada, Northwest Region, Northern Forestry Centre, Edmonton, Alberta, Information Report NOR-X-329. 22 p.</ref> || EBS&nbsp;D (part)<ref name=Anderson1980/> || Massachusetts,<ref name=Anderson1980/> Quebec.<ref name="mall1"/>
|-
| NABS&nbsp;VII || Armillaria gallica {{au|(Marxmüller & Romagn.)}} || || Vermont, Michigan,<ref name=Anderson1980/> [[British Columbia]]<ref name="mall1">Mallett, K. I. (1990). "''Armillaria'' [[root rot]] pathogens of the Canadian prairie provinces". ''Canadian Journal of Forest Research'' 20:1859–1863.</ref>
|-
| NABS&nbsp;VIII || || EBS&nbsp;D (part + rg)<ref name=Anderson1980/> || New York, Michigan.<ref name=Anderson1980/>
|-
| NABS&nbsp;IX || ''Armillaria nabsnona'' {{au|T. J. Volk & Burds. (1996)}} || || Idaho, British Columbia.<ref name=Anderson1980/>
|-
| NABS&nbsp;X || ''Armillaria altimontana'' {{au|Brazee, B. Ortiz, Banik & D. L. Lindner (2012)}} || NABS&nbsp;V, NABS&nbsp;XI (both <5%)<ref name="Banik"/> || Idaho,<ref name=Anderson1980/> British Columbia.<ref name="mall1"/>
|-
| NABS&nbsp;XI<ref name="mall2"/> || ''Armillaria cepistipes'' {{au|Velen. (1920)}}<ref name="Banik"/> || EBS&nbsp;B (57%)<ref name="Banik"/> || British Columbia<ref name="mall1"/>
|}

Similar lists of biological species have been constructed by mycologists working in Japan (10 as of 1998)<ref>{{cite journal |last1=Ota |first1=Y. |last2=Matsushita |first2=N. |last3=Nagasawa |first3=E. |last4=Terashita |first4=T. |last5=Fukuda |first5=K. |last6=Suzuki |first6=K. |title=Biological Species of Armillaria in Japan |journal=Plant Disease |date=May 1998 |volume=82 |issue=5 |pages=537–543 |doi=10.1094/PDIS.1998.82.5.537}}</ref> and China (16 as of 2024).<ref name=Liu24>{{cite journal |last1=Liu |first1=Jianwei |last2=Qin |first2=Guofu |last3=Chen |first3=Jian |last4=Song |first4=Jing |last5=Yan |first5=Zhuyue |last6=Yang |first6=Shimei |last7=Tian |first7=Meng-Hua |last8=Xu |first8=Xin |last9=Zhang |first9=Changfei |last10=Luangharn |first10=Thatsanee |last11=Bhunjun |first11=Chitrabhanu S. |last12=Yu |first12=Fuqiang |last13=Yang |first13=Zhu L. |title=Armillaria korhonenii, the sixteenth biological species of Armillaria from China |journal=Phytotaxa |date=20 February 2024 |volume=637 |issue=2 |pages=149–164 |doi=10.11646/phytotaxa.637.2.3 |url=https://www.researchgate.net/publication/378312373_Armillaria_korhonenii_the_sixteenth_biological_species_of_Armillaria_from_China}}</ref>

Further data from molecular diagnostic tools have removed much uncertainty for mycologists and forest pathologists. New questions remain unanswered regarding the phylogeny of North American ''Armillaria'' species and their relationships to their European counterparts, particularly within the "''Armillaria mellea'' complex". Some data suggest that North American and European ''A. gallica'' isolates are not monophyletic. Although North American and European isolates of ''A. gallica'' may be interfertile, some North American isolates of ''A. gallica'' are more closely related to the North American taxon ''A. calvescens'' than to European isolates of ''A. gallica''. The increase in genetic divergence has not necessarily barred inter-sterility between isolated populations of ''A. gallica''. Although the relationships among some groups in the genus seem clearer, the investigation of geographically diverse isolates has revealed that the relationship between some North American species is still unclear (Hughes et al. 2003).<ref name="hugh">Hughes, M. B.; Weir, A.; Rogers, S. O. (2003). "Phylogenetic reconstruction of North American ''Armillaria'' species and related European taxa based on nuclear ribosomal DNA internal transcribed spacers". p. 32 in Laflamme, G.; Bérubé, J. A.; Bussières, G. (eds.), ''Root and Butt Rots of Forest Trees. Proceedings of the 10th International Conference of Root and Butt Rots'', IUFRO Working Party 7.02.01, Quebec, September 2001. Natural Resources Canada, Canadian Forest Service, Information Report LAU-X-126. 450 p.</ref> A similar situation happens in China, where some molecular phylogenetic data appear to line up with intersterile "biological species" and others do not.<ref name=Liu24/>

''Armillaria'' root rot occurs in the [[Northwest Territories]],{{citation needed|date=May 2017}} and was identified on [[white spruce]] at [[Pine Point, Northwest Territories|Pine Point]] on [[Great Slave Lake]] prior to NABS&nbsp;findings.{{citation needed|date=May 2017}}

=== ''Rhizomorpha'' ===
In 1791 [[Albrecht Wilhelm Roth]] described the species ''Rhizomorpha fragilis'' for a collection which consisted entirely of rhizomorphs.  The genus ''[[Rhizomorpha]]'' thus became established and later these [[mycelial]] cords were shown to belong to ''Armillaria mellea''.  According to the [[International Code of Nomenclature for algae, fungi, and plants|code of nomenclature]] that means that the two genus names are synonyms and since genus ''Armillaria'' was not defined until 1857, the name ''Rhizomorpha'' takes precedence and should replace the name ''Armillaria''. To avoid this, a 2021 paper by Stalpers et al. proposes that the name ''Armillaria'' should be protected. The proposal awaits decisions by the [[Nomenclature Committee for Fungi]] and eventually by an [[International Botanical Congress]].<ref name="IF_Rhizomorpha">{{cite web |url=http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=18461 |title=the ''Rhizomorpha'' page |work=Species Fungorum |publisher=Royal Botanic Gardens Kew |access-date=2020-09-05 }}</ref><ref name="Koch2018">{{cite journal |vauthors=Koch RA, Lodge DJ, Sourell S, Nakasone K, McCoy AG, Aime MC |title=Tying up loose threads: revised taxonomy and phylogeny of an avian-dispersed Neotropical rhizomorph-forming fungus |journal=Mycological Progress |year=2018 |volume=17 |issue=9  |pages=989–998 |doi=10.1007/s11557-018-1411-8 |doi-access=free |bibcode=2018MycPr..17..989K |url=https://www.researchgate.net/publication/325653310}}</ref><ref name="Stalpers2021">{{cite journal |vauthors=Stalpers JA, Redhead SA, May TW |display-authors=etal |title=Competing sexual-asexual generic names in Agaricomycotina (Basidiomycota) with recommendations for use |journal=IMA Fungus |year=2021 |volume=12 |issue=22 |page=3  |pmid=34380577|  doi=10.1186/s43008-021-00061-3| pmc=8359032 |doi-access=free }}</ref>