Ulmus × hollandica 'Ypreau' is one of a number of cultivars arising from the crossing of the Wych Elm

Wych Elm

Ulmus glabra, the Wych elm or Scots elm, has the widest range of the European elm species, from Ireland eastwards to the Urals, and from the Arctic Circle south to the mountains of the Peloponnese in Greece; it is also found in Iran...

 U. glabra with a variety of Field Elm

Field Elm

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; its northern outposts are the Baltic islands of Öland and Gotland, although it...

 U. minor. The tree was first identified by Poederlé http://asaweb.huh.harvard.edu:8080/databases/botanists?id=101407 in Man. Arb. For. Belg. 266, 1772, as l'orme Ypreau.

Cultivation

Poederlé's orme Ypreau is probably extinct, unless indeed it is the same hybrid that was still called ypreau or ypereau in the Somme and Picardy areas in the late nineteenth century, which, according to R. H. Richens, was Ulmus × hollandica 'Major'. Richens concluded, on the basis of field studies, that Picardy was the provenance of the 'Dutch' elm planted in England. The latter also has large heart-shaped Tilia

Tilia

Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...

-like leaves.

Etymology

The word Ypreau or ypereau was first recorded in 1432 from the Pas-de-Calais area, and found its way into Cotgrave's

Randle Cotgrave

Randle Cotgrave , may possibly be Randal, son of William Cotgreve of Christleton in Cheshire, who is mentioned in the pedigree of the Cotgreve family, contained in Harl. MS. 1500, fol...

 French-English dictionary of 1611 as a name for a large-leafed elm, as distinct from the small-leaved types of Ulmus minor in northern France. It derives from a north German word for elm, ip or iper that became iep in Dutch and iperen in Frisian, and reached French from Flemish. The tree was once commonly planted in the region of Ypres

Ypres

Ypres is a Belgian municipality located in the Flemish province of West Flanders. The municipality comprises the city of Ypres and the villages of Boezinge, Brielen, Dikkebus, Elverdinge, Hollebeke, Sint-Jan, Vlamertinge, Voormezele, Zillebeke, and Zuidschote...

, Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, but does not take its name from the town.

The cultivar name 'Ypreau' has also been given to varieties of Poplar

Poplar

Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

 and Willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

, resulting in some confusion.