Editing Armillaria (section)

== Description ==
[[File:Armillaria mellea 041031w.jpg|thumb|180px|right|''[[Armillaria mellea]]'']]
[[File:Armillaria sp Marriott edit.jpg|thumb|''[[Armillaria hinnulea]]'']]

The basidiocarp (reproductive structure) of the fungus is a [[mushroom]] that grows on wood, typically in small dense clumps or tufts. Their [[pileus (mycology)|caps]] (mushroom tops) are typically yellow-brown, somewhat sticky to touch when moist, and, depending on age, may range in shape from [[wikt:conical|conical]] to [[wikt:convex|convex]] to depressed in the center. The [[stipe (mycology)|stipe]] (stalk) may or may not have a [[annulus (mycology)|ring]]. All ''Armillaria'' species have a white [[spore print]] and none have a [[volva (mycology)|volva]] (cup at base).<ref name=":0">{{Cite book |last=Pegler DN |title=''Armillaria'' Root Rot: Biology and Control of Honey Fungus |publisher=Intercept |year=2000 |isbn=1-898298-64-5 |editor-last=Fox RTV |pages=81–93 |chapter=Taxonomy, nomenclature and description of ''Armillaria''}}</ref>

''Armillaria'' species are long-lived and form the [[Largest organisms|largest living fungi]] in the world.<ref>{{Cite journal |last=Smith |first=Myron L. |last2=Bruhn |first2=Johann N. |last3=Anderson |first3=James B. |date=April 1992 |title=The fungus Armillaria bulbosa is among the largest and oldest living organisms |url=https://www.nature.com/articles/356428a0 |journal=Nature |language=en |volume=356 |issue=6368 |pages=428–431 |doi=10.1038/356428a0 |issn=1476-4687}}</ref> The largest known organism (of the species [[Armillaria ostoyae|''A.&nbsp;ostoyae'']]) covers more than {{convert|3.4|sqmi|km2}} in [[Oregon]]'s [[Malheur National Forest]] and is estimated to be 2,500 years old.<ref name="Ingraham2010">{{cite book |author=John L. Ingraham |url=https://books.google.com/books?id=lbdfRcxIbLIC&pg=PA201 |title=March of the Microbes: Sighting the Unseen |date=15 February 2010 |publisher=Harvard University Press |isbn=978-0-674-03582-9 |page=201}}</ref><ref name="si">{{cite web |last1=Daley |first1=Jason |date=15 October 2018 |title=This Humongous Fungus Is as Massive as Three Blue Whales |url=https://www.smithsonianmag.com/smart-news/mushroom-massive-three-blue-whales-180970549/ |access-date=21 October 2018 |website=Smithsonian.com |publisher=Smithsonian Institution}}</ref> Some species display [[bioluminescence]], known as [[foxfire]].

=== Similar species ===
Similar species include ''[[Pholiota]]'' spp. which also grow in cespitose (mat-like) clusters on wood and fruit in the fall. ''Pholiota'' spp. are separated from Armillaria by its yellowish to greenish-yellow tone and a dark brown to grey-brown spore print. [[Mushroom hunter]]s need to be wary of ''[[Galerina]] '' spp. which can grow side by side with ''Armillaria'' spp. on wood. ''[[Galerina]]'' have a dark brown spore print and are deadly [[Mushroom poisoning|poisonous]] ([[alpha-amanitin]]).

The white spore print and lack of volva can be compared to ''[[Amanita]]''.<ref name=":0" /> As a [[white rot]], it is distinguished from ''[[Tricholoma]]'', a [[mycorrhiza]]l (non-parasitic) genus.