Ulmus minor Mill., the Field Elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern outposts are the Baltic islands of Öland and Gotland, although it may have been introduced here by man. The tree's typical habitat is low-lying forest along the main rivers, growing in association with oak and ash, where it tolerates summer floods as well as droughts.