Ulmus × hollandica Mill. , often known simply as Dutch elm, is a natural hybrid between wych elm (U. glabra) and field elm (U. 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,Richens, R. H., Elm (Cambridge 1983), p. 95, 233 "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". Crosses between U. × hollandica and either of the parent species are also classified as U. × hollandica.Richens, R. H., Elm (Cambridge, 1983), p.5

The botanical name hollandica was first used for an elm variety by Plukenet in 1697 in describing a cultivar of this group now called 'Major'.Plukenet, Almagestum botanicum, p.329Richens, R. H., Elm (Cambridge 1983), p.80 Elms exported from the Netherlands to Germany in 1634 as 'Dutch elms' may have been 'Major'.Goudzwaard, Leo, Loofbomen in Nederland en Vlaanderen (Zeist, 2013)

Description In form and foliage, the trees are broadly intermediate between the two species.Collin, E. (2001). Elm. In Teissier du Cros (Ed.) (2001) Forest Genetic Resources Management and Conservation. France as a case study. Ministry of Agriculture and Fisheries, Bureau of Genetic Resources. INRA DIC. France. F1 hybrids between wych and field elm are fully fertile, but produce widely variant progeny.Richens, R. H. (1983), Elm Many also inherit the suckering habit of their field elm parent.Clouston, Brian, & Stansfield, Kathy, eds.: After the Elm (Heinemann, London, 1979) Both Richens and Rackham noted that examples in the East Anglian hybridization zone were sometimes pendulous in form.Oliver Rackham, A History of the Countryside (London, 1986) In 1948 Melville described the experience of researching near the Hertfordshire-Essex border: "Groups of related hybrids occupy some of the valleys, forming distinct local races. Often, on passing over the brow of a hill from one valley to the next the elm population changes."Melville, Ronald, 'The British Elms', in The New Naturalist: a journal of British natural history (Collins, London, 1948), p.38

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

Cultivation Ulmus × hollandica hybrids, natural and artificial, have been widely planted outside their zones of origin.Bean, W. J. (1981). Trees and shrubs hardy in Great Britain, 7th edition. Murray, LondonElwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. 1848–1929. Private publication, Edinburgh. Within their zones of origin they were often the tree of choice for lining streets, roads, canals and dykes, as in Flanders and the Low Countries.

The hybrid has been introduced to North America and Australasia.

"Lineage elms" Oliver Rackham used the term "Lineage elms" for local homogeneous Ulmus × hollandica hybrids, not nursery-sourced, that had arisen naturally in patches of woodland in the hybridization zone (mainly north Essex and south Suffolk) and had been cultivated within a small area, such as a village or parish, down the generations, for coppicing. They were said to coppice as well as wych, and to be non-invasive.Rackham, Oliver, Ancient Woodland: its history, vegetation and uses in England (London, 1980) He gave as an example the elms of Groton Wood, Suffolk.Rackham, Oliver, Trees and Woodland in the British Landscape, (revised edition, London 1990), p.128 In his early publications he had referred to them as "the unnamed coppice elms of some eastern woods"Rackham, Oliver, Trees and Woodland in the British Landscape, (London 1976), p.36 He later settled on "Lineage elms", perhaps with reference to Lineage Wood near Long Melford, Suffolk, one of his study-areas.Rackham, Oliver, Trees and Woodland in the British Landscape, (revised edition, London 1990), p.86-87Rackham, Oliver The History of the Countryside: the full fascinating story of Britain's landscape (London, 1986)

Notable trees The great elm in The Grove of Magdalen College, Oxford, photographed by Henry Taunt in 1900, long believed to be a wych elm before being identified by Elwes as a 'Vegeta'-type hybrid, was for a time the largest elm known in Britain before it was blown down in 1911. It measured 44 m tall, its trunk at breast height being 2.6 m in diameter, and comprised an estimated of timber,1911 photograph of the great elm at Magdalen College, fallen: Maxwell, Herbert, Trees: a Woodland Notebook, Containing Observations on Certain British and Exotic Trees (Glasgow, 1915), p.55: gutenberg.org making it the largest tree of any kind in Britain and possibly the largest north of the Alps.Editorial, Quarterly Journal of Forestry 5 (1911). 'An enormous elm'. 278–280. Royal Forestry Society. However, as Elwes pointed out, its calculated age would place its planting in the late 17th or early 18th century,Peter Fullerton, 'A Tale of Three Trees', Magdalen College Newsletter, 1998 long before the introduction of the Huntingdon elm, making the tree in question more likely to be a Chichester elm. A second tree nearby, described by Elwes as "similar in habit and foliage" Labelled U. hollandica aff. vegeta, Magdalen College Grove specimen 1 (Heybroek, Oxford 1958); Labelled U. hollandica aff. vegeta, Magdalen College Grove specimen 2 (Heybroek, Oxford 1958) and tall by in girth in 1912,Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland . Vol. VII. p.1881–1882. Republished 2004 Cambridge University Press, was confirmed by Nellie Bancroft in a Gardener's Chronicle article in 1934 as a 'Vegeta'-type hybrid;Bancroft, H. 1934. Notes on the status and nomenclature of the British elms. V. – Elms generally accepted as hybrids, the Dutch Elm. The Gardeners’ Chronicle, 96: 298-299. it was propagated by Heybroek in 1958 and cultivated at the Baarn elm research institute as clone P41.bioportal.naturalis.nl, specimen L.1582476Heybroek's clones P41 and P141, also from Magdalen College, were planted in a field trial in the Flevopolder in The Netherlands. The tree survived till the 1960s. Like the Queens' College Chichester elms in Cambridge, the Magdalen College trees were not observed to produce root suckers, though The Grove at Magdalen has long been a deer park, and any sucker growth is likely to have been cropped. The Oxford zoologist Robert Gunther attributed the larger tree's unusual size to the fact (discovered in 1926) that it had been growing on a phosphate-rich bone-bed, made up of the remains of mammoths and other prehistoric animals.Gunther, R. T., 'Mammoth bones that made elms gigantic: Oxford discoveries', The Illustrated London News, 30 January 1926, p.175

With a girth of 6.9 m (22.6 ft) and a height of , the Ulmus × hollandica hybrid elm on Great Saling Green, Great Saling, near Braintree, Essex, reckoned at least 350 years old, was reputedly the largest elm in England, before succumbing to Dutch Elm Disease in the 1980s;R. H. Richens, Elm, p.243 Elwes and Henry (1913) misidentified it as U. nitens (Ulmus minor).

Examples of mature survivors in the East Anglian hybridisation zone include those near Royston, Hertfordshire, designated 'Elm of the Year, 2004' by Das Ulmen Büro.U. x hollandica hybrids (to judge by branching, perhaps not 'Huntingdon' clones), Burloes, near Royston, Hertfordshire, Das Ulmen Büro 'Elm of the Year, 2004', Dr. Gordon Mackenthun An example of the weeping form survives at Actons Farm, Sawbridgeworth, Hertfordshire.Google Maps: England - Google Maps, accessdate: July 27, 2016

There are two notable TROBI Champion trees in the British Isles, one at Little Blakenham, Suffolk, measuring d.b.h. in 2008, the other at Nounsley, Essex, high by d.b.h. in 2005.Johnson, O. (2011). Champion Trees of Britain & Ireland,  p. 169. Kew Publishing, Kew, London. .

A large old Ulmus × hollandica in Pioneer Park, Agassiz, British Columbia (2023, about 40 m tall, bole-girth 6 m), is believed to have been planted c.1870.Ira Sutherland, 'The giant elm of Agassiz', Vancouver Big Tree Hiking Guide, vancouversbigtrees.com

The so-called W. G. Grace Elm, a majestic spreading hybrid (labelled just "Dutch elm"), the last survivor (2009) of a ring of elms round East Oval, Ballarat, Victoria, was reputedly planted by W. G. Grace himself in 1874 during a tour by the England cricket team.The W. G. Grace Elm, Ballarat, nationalregisterofbigtrees.com.au It has been shown, however, to date from 1900.'The history of this famous Ballarat tree isn't what it seems'; The Courier, Ballarat, 21 May 2018 'W. G. G.' had attained a spread round the middle of 31 m by 1982.The W. G. Grace Elm, Ballarat, vhd.heritage.vic.gov.au

Cultivars At least 40 cultivars have been recorded, although some may not have survived Dutch elm disease:

Others provisionally identified as Ulmus × hollandica include 'Scampstoniensis' and 'Virens' (by Green); 'Purpurea' and 'Louis van Houtte' (by F. J. Fontaine); 'Escaillard' and 'Hillieri' (by Buisman); 'Rugosa Pendula' (by Arnold and Morton arboreta); and Späth's 'Fastigiata Glabra' (by Melville). Cultivars at one time or another identified as U. × hollandica, but which may have suffered misidentification through confusion with U. glabra Huds. cultivars that share the same name include 'Fastigiata Glabra', 'Fastigiata Macrophylla', 'Latifolia', and 'Rugosa'. In the 19th century and early 20th, Ulmus × hollandica cultivars (as well as those of wych elm) were often grouped under Ulmus montana. Republished 2004 Cambridge University Press,

In art The elms in the Suffolk landscape-paintings and drawings of John Constable were "most probably East Anglian hybrid elms ... such as still grow in the same hedges" in Dedham Vale and East Bergholt.R. H. Richens, Elm, p.166, 179 (His Flatford Mill elms were U. minor.Richens, R. H., Elm (Cambridge 1983), p.173; p.293, note 26) Elm trees in Old Hall Park, East Bergholt, showing a clump of these hybrids, is often considered the finest of Constable's elm-studies.R. H. Richens, Elm, p.178Wilkinson, Gerald, Epitaph for the Elm (London, 1978)

Accessions

North America Arnold Arboretum, US. Acc. nos. 325-81, 7614, 92-38 Bartlett Tree Experts, US. Acc. nos. 1245, 1246 New York Botanical Garden, US. Acc. no. 508/79 Niagara Parks Botanical Gardens, US. Acc. no. 940414

Europe Sir Harold Hillier Gardens, UK. Acc. no. 1977.0615 Wijdemeren City Council, Netherlands. Elm collection. Frans Halslaan, Loosdrecht (~1960)

Australasia Eastwoodhill Arboretum , Gisborne, New Zealand. 24 trees, details not known. Waite Arboretum , University of Adelaide, Adelaide, Australia. Acc. nos. 368, 339

Nurseries

North America

None known.

Europe Boomwekerijen 'De Batterijen' , Netherlands.

Australasia Fleming's Nursery , Monbulk, Victoria, Australia

Notes

References