Technically both Amanita muscaria var. flavivolvata and Amanita muscaria subsp. flavivolvata are valid. However, to ensure that we aren’t exporting both to third parties like EOL, I’m suggesting that we prefer the subspecies. This follows what Rod is currently doing on Amanitaceae.org and I believe there is good evidence that this is a distinct species that will eventually be published as Amanita amerimuscaria. Given this subspecies status seems more appropriate than a variety.