|Ulmus procera subsp. var.||English Elm|
Ulmus procera Salisb., the English Elm or Atinian Elm was, before the advent of Dutch elm disease, one of the largest and fastest-growing deciduous trees in Europe. A survey of genetic diversity in Spain, Italy and the UK revealed that the English Elms are genetically identical, clones of a single tree, the Atinian Elm once widely used for training vines, and brought to the British Isles by Romans for the purpose of supporting and training vines. Thus, the origin of U. procera is widely believed to be Italy, although it is possible the tree hailed from what is now Turkey, where it is still used in the cultivation of raisins.
The leaves are dark green, almost orbicular, < 10 cm long, without the pronounced acuminate tip at the apex typical of the genus. Wind-pollinated, the small, reddish-purple hermaphrodite apetalous flowers appear in early spring before the leaves . The tree does not produce fertile seed as it is female-sterile, and propagation is entirely by root suckers. 
Pests and diseases
Owing to its homogeneity, the tree has proven particularly susceptible to Dutch elm disease, but immature trees remain a common feature in the English countryside courtesy of the ability to sucker from roots. After about 20 years, these suckers too become infected by the fungus and killed back to ground level. English Elm was the first elm to be genetically engineered to resist disease, at the University of Abertay Dundee. It was an ideal subject for such an experiment, as its sterility meant there was no danger of its introgression into the countryside.
The leaves of the English Elm in the UK are mined by Stigmella ulmivora.
- ↑ Tree News, Spring/Summer 2005,Publisher Felix Press, 
- ↑ http://news.bbc.co.uk/2/hi/science/nature/3959561.stm
- ↑ Bean, W. J. (1981). Trees and shrubs hardy in Great Britain. Murray, London.
- ↑ Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. pp 1848-1929. Private publication. 
- ↑ Richens, R. H. (1983). Elm. Cambridge University Press
- ↑ Stace, C. A. (1997). New Flora of the British Isles. Cambridge University Press.
- ↑ White, J. & More, D. (2002). Trees of Britain & Northern Europe. Cassell's, London
- ↑ 
- ↑ Miller, F., Ware, G. and Jackson, J. (2001). Preference of Temperate Chinese Elms (Ulmuss spp.) for the Feeding of the Japanese Beetle (Coleoptera: Scarabaeidae). Journal of Economic Entomology 94 (2). pp 445-448. 2001. Entom. Soc.of America.
- ↑ Green, P. S. (1964). Registration of cultivar names in Ulmus. Arnoldia, Vol. 24. Arnold Arboretum, Harvard University.