 Sequencing confirmed that this species originated from "E. × robertsii", a sterile triploid hybrid between "E. guttata" and "E. lutea," both of which have been introduced and naturalised in the United Kingdom.New populations of "E. peregrina" arose on the Scottish mainland and the Orkney Islands via genome duplication from local populations of "E. × robertsii".Because of a rare genetic mutation, "E. peregrina" is not sterile.