Ulmus × hollandica

Ulmus × hollandica
The Great Saling elm (1906), identified by R. H. Richens as U. × hollandica (possibly older than the earliest named cultivar of this group in England, 'Dutch Elm')
Hybrid parentage	U. glabra × U. minor
Cultivar	Ulmus × hollandica

Ulmus × hollandica Mill. , often known simply as Dutch elm, is a natural hybrid between Wych elm Ulmus glabra and field elm Ulmus minor which commonly occurs across Europe wherever the ranges of the parent species overlap. In England, according to the field-studies of R. H. Richens, "The largest area [of hybridization] is a band extending across Essex from the Hertfordshire border to southern Suffolk. The next largest is in northern Bedfordshire and adjoining parts of Northamptonshire. Comparable zones occur in Picardy and Cotentin in northern France".

Ulmus × hollandica hybrids, natural and artificial, have been widely planted elsewhere by man.

In form and foliage, the trees are broadly intermediate between the two species.F1 hybrids between Wych and field elm are fully fertile, but produce widely variant progeny. Many also inherit the suckering habit of their field elm parent. Both Richens and Rackham noted that examples in the East Anglian hybridization zone were sometimes pendulous in form.

Hedgerow U. x hollandica, Lincolnshire

Flowers of same

Some examples of the hybrid possess a moderate resistance to Dutch elm disease.

The hybrid has been introduced to North America and Australasia.

The great elm in the Grove of Magdalen College, Oxford, photographed by Henry Taunt in 1900 and said by Elwes to be the largest elm in Great Britain, was long believed to be a wych elm but was found on examination by Elwes and Henry to be a Huntingdon-type hybrid that at c.300 years old pre-dated the cultivation of Huntingdon Elm. When it blew down in 1911, it had been 43.7 metres (143 ft) high and 8.3 metres (27 ft) in girth and comprised an estimated 81 cubic metres (2,900 cu ft) of timber. It was considered the largest tree of any kind in Britain, and possibly the largest tree north of the Alps.