| Ulmus × hollandica | |
|---|---|
| Ulmus × hollandica 'Vegeta' (Huntingdon Elm) | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Rosids |
| Order: | Rosales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Species: | U. hollandica |
| Binomial name | |
| Ulmus hollandica Mill. |
|
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 two parent species overlap. In England, according to the field-studies of R. H. Richens,[1] "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".
F1 hybrids between Wych and Field Elm are fully fertile, but produce widely variant progeny.[2] Many also inherit the suckering habit of their Field Elm parent.[3] Both Richens and Rackham noted that examples in the East Anglian hybridization zone were sometimes pendulous in form.[2][4] A surviving mature U. × hollandica at Actons Farm, Sawbridgeworth, Hertfordshire - if it was not, as has been suggested, a seedling of Vegeta (Huntingdon Elm) from the local Rivers Nursery (see under Vegeta) - is a case in point.
U. × hollandica hybrids, natural and artificial, have been widely planted elsewhere by man.[2][5][6]
Contents |
In form and foliage, the trees are broadly intermediate between the two species.[7]
Some examples of the hybrid possess a moderate resistance to Dutch elm disease.[8]
The hybrid has been introduced to North America and Australasia.
With a girth of 22 feet 6 inches (6.86 m) and a height of 40 metres, the Ulmus x hollandica hybrid elm on Great Saling Green, Great Saling, near Braintree, Essex, was reputedly the largest elm in England, before succumbing to Dutch Elm Disease in the 1980s.[9] A photograph of the tree can be found (plate 402) in Elwes & Henry's Trees of Great Britain & Ireland [2] published in 1913, wherein it is identified as U. nitens (U. minor subsp. minor).[6]
Examples of mature survivors in the East Anglian hybridisation zone include the elms at the River Can weir, at the western end of Admiral's Park, Chelmsford, Essex, and those near Royston, Hertfordshire, designated 'Elm of the Year, 2004' by Das Ulmen Büro.[10]
Many old trees still survive in New Zealand, notably in Auckland, the finest considered to be the specimen found outside the Ellerslie Racecourse.[11]
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, Flatford and East Bergholt.[12] Elm trees in Old Hall Park, East Bergholt [3] is often considered the finest of Constable's elm-studies.[13]
At least 30 cultivars have been recorded, although over half have now been lost to cultivation because of Dutch elm disease:
None known.