Here is how Bitcoin could be taxed:
The tax office gives a sheet of paper to every merchant that uses Bitcoin and asks them to write down the amount of Bitcoins they received. Then the tax office decides how much taxes they should pay and asks them to transfer the appropriate amount to the Bitcoin address of the tax office.
Tax offices deal in their sovereign fiat - they won't have bitcoin wallets, or litecoin wallets, or dogecoin wallets - funny as that might be
