 A 2006 molecular phylogenetic study of different regional populations of A. muscaria by mycologist József Geml and colleagues found three distinct clades within this species representing , roughly , Eurasian , Eurasian " subalpine " , and North American populations . Specimens belonging to all three clades have been found in Alaska ; this has led to the hypothesis that this was the centre of diversification for this species . The study also looked at four named varieties of the species : var. alba , var. flavivolvata , var. formosa ( including var. guessowii ) , and var. regalis from both areas . All four varieties were found within both the Eurasian and North American clades , evidence that these morphological forms are polymorphisms rather than distinct subspecies or varieties . Further molecular study by Geml and colleagues published in 2008 show that these three genetic groups , plus a fourth associated with oak – hickory – pine forest in the southeastern United States and two more on Santa Cruz Island in California , are delineated from each other enough genetically to be considered separate species ; thus A. muscaria as it stands currently is evidently a species complex . The complex also includes at least three other closely related taxa that are currently regarded as species : A. breckonii is a buff @-@ capped mushroom associated with conifers from the Pacific Northwest , and the brown @-@ capped A. gioiosa and A. heterochroma from the Mediterranean Basin and from Sardinia respectively . Both of these last two are found with Eucalyptus and Cistus trees , and it is unclear whether they are native or introduced from Australia . 
 A 2006 molecular phylogenetic study of different regional populations of A. muscaria by mycologist József Geml and colleagues found three distinct clades within this species representing , roughly , Eurasian , Eurasian " subalpine " , and North American populations . Specimens belonging to all three clades <a href='been_done' title='1'><mark>have</mark></a> been found in Alaska ; this <a href='been_done' title='2'><mark>has</mark></a> led to the hypothesis that this was the centre of diversification for this species . The study also looked at four named varieties of the species : var. alba , var. flavivolvata , var. formosa ( including var. guessowii ) , and var. regalis from both areas . All four varieties <a href='uninflect' title='3'><mark>were</mark></a> found within both the Eurasian and North American clades , evidence that these morphological forms <a href='drop_aux' title='4'><mark>are</mark></a>polymorphisms rather than distinct subspecies or varieties . Further molecular study by Geml and colleagues published in 2008 show that these three genetic groups , plus a fourth associated with oak – hickory – pine forest in the southeastern United States and two more on Santa Cruz Island in California , are delineated from each other enough genetically to be considered separate species ; thus A. muscaria as it <a href='uninflect' title='5'><mark>stands</mark></a> currently <a href='drop_aux' title='6'><mark>is</mark></a>evidently a species complex . The complex also <a href='uninflect' title='7'><mark>includes</mark></a> at least three other closely related taxa <a href='null_relcl' title='8'><mark>that</mark></a>are currently regarded as species : A. breckonii is a buff @-@ capped mushroom associated with conifers from the Pacific Northwest , and the brown @-@ capped A. gioiosa and A. heterochroma from the Mediterranean Basin and from Sardinia respectively . Both of these last two are found with Eucalyptus and Cistus trees , and it is unclear whether they are native or introduced from Australia . 
A 2006 molecular phylogenetic study of diff regional populations of A. muscaria by mycologist József Geml and colleagues found three distinct clades within this species reppin , roughly , Eurasian , Eurasian " subalpine " , and North American populations . Specimens belonging to all three clades done been found in Alaska ; this done led to the hypothesis dat dis was da centre of diversification for this species . Tdastudy also looked at four named varieties of thdapecies : var. alba , var. flavivolvata , var. formosa ( including var. guessowii ) , and var. regalis from both areas . All four varieties was found within both thedarasian and North American clades , evidence that dese morphological forms polymorphisms rather than distinct subspecies or varieties . Further molecular study by Geml and colleagues published in 2008 show that tdemthree genetic groups , plus a fourth associated wit oak – hickory – pine forest in the southeastern United States and 2 more on Santa Cruz Island in cali , r delineated from each other enough genetically to b considered separate species ; thus A. muscaria as it stand currently evidently a species complex . The complex also include at least three other closely related taxa are currently regarded as species : A. breckonii is a buff @-@ capped mushroom associated wwitconifers from the Pacific Northwest , and the brown @-@ capped A. gioiosa and A. heterochroma from the Mediterranean Basin and from Sardinia respectively . Both of thedemst tw2rround wiwiducalyptus and Cistus trees , and it is unclear whether they are native or introduced from Australia .