Ulmus Minor

Ulmus minor, 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; 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.

Current treatment of the species owes much to Richens, who sank a number of British elms as either subspecies or varieties in 1968. However, Melville, writing 10 years later, identified five distinct species, several varieties and numerous complex hybrids. In 1992, 14 years after Melville, Armstrong identified no fewer than 40 species and microspecies. Stace (1997) wrote of the British elms "The 2-species (glabra and minor) concept of Richens is not sufficiently discriminating to be of taxonomic value". Nevertheless, it is Richens’ classification which has been the most commonly adopted in recent years, although it is not used in Flora Europaea .

In 2009 Dr Max Coleman of the Royal Botanic Garden, Edinburgh wrote: "The advent of DNA fingerprinting has shed considerable light on the question. A number of studies have now shown that the distinctive forms Melville elevated to species and Richens lumped together as field elm are single clones, all genetically identical, which have been propagated by vegetative means such as cuttings or root suckers. This means that enigmatic British elms such as Plot's Elm and English Elm have been shewn to be single clones of Field Elm. Although Richens did not have the evidence to prove it, he was correct in recognising a series of clones and grouping them together as a variable species."

It is hoped that analysis of molecular markers will ultimately eliminate the taxonomic confusion.