Ulmus americana 'Washington'

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Ulmus americana
Cultivar
'Washington'
Origin
USA

The American Elm Ulmus americana cultivar 'Washington' is a tree of unknown derivation. Introduced by the U. S. National Park Service, it has been described as possibly having triploid chromosome levels (unusual for an American Elm), suggesting it may be a hybrid between the tetraploid American Elm and a diploid species. However, in view of a study performed by the United States National Arboretum in 2004 [1], this earlier supposition is likely to be erroneous; therefore, like the cultivar 'Jefferson' which was also once considered triploid, 'Washington' is probably tetraploid. The tree is resistant to Dutch elm disease, but less so than other American Elm cultivars such as 'Valley Forge'. Neither 'Washington' nor 'Jefferson' has been widely tested beyond Washington D.C..

The tree is not known to have been introduced to Europe or Australasia.

[edit] Arboreta etc. accessions

[edit] North America

• Brooklyn Botanic Garden [2], New York, acc. no. 850233.
• Smith College, acc. no. 41703.

[edit] External links

• http://fletcher.ces.state.nc.us/programs/nursery/metria/metria11/warren/elm.htm Return of the Elm -the status of elms in the nursery industry in 2000. Warren, K., J. Frank Schmidt and Co.