Armillaria ostoyae in North America has undergone a name change to Armillaria solidipes so that these two different species can be distinguished from one another. I have no confirmed DNA evidence of A. ostoyae existing in North America from 1000s of collections. The ruling to conserve the name A. ostoyae should only be applied to collections from Europe and Asia.

Note: "I concur that Armillaria solidipes is the correct name for 'North American A. ostoyae.' Years ago, I corresponded with Scott Redhead, who was lead author on the proposal to conserve the name Armillaria ostoyae, which was approved. Scott conveyed that their proposal to conserve the name A. ostoyae for the North American species applies only if the North American and Eurasian species are the same. He and many others have concluded that ample evidence demonstrates that the North American and Eurasian species are not the same, and they should not be treated as synonyms (e.g., Guo et al 2016 and multiple other papers), thus, A. solidipes is the appropriate name for what was formerly called North American A. ostoyae. In fact, we have been chastised by multiple reviewers for even suggesting that A. solidipes is sometimes referred to as A. ostoyae." - Dr. Ned Klopfenstein