Correction to: Nature Ecology & Evolution https://doi.org/10.1038/s41559-017-0347-8, published online 30 October 2017.

In the version of this Article originally published, it was incorrectly stated that “16,687 protein-coding genes were inferred for the most recent common ancestor (MRCA) of Armillaria”; the value was incorrect and it should have read “15,787”. This has now been corrected.