Ulmus americana 'Delaware'
Encyclopedia
The American Elm
Ulmus americana cultivar 'Delaware' was originally selected (as tree number 218) from 35,000 seedlings inoculated with the Dutch elm disease
fungus in USDA trials at Morristown
, New Jersey
.
which confirmed the clone had a fair level of resistance to Dutch elm disease. 'Delaware' is susceptible to Elm Yellows
, but resistant to the Elm Leaf Beetle Xanthogaleruca luteola
.
, Washington, D. C. in 1948, died from unknown causes (probably elm yellows, by some accounts) in 1980, but a clone survives at the Denver Botanic Gardens
, as 'Delaware II'. Although propagated for further trials, the tree was never commercially released owing to its poor shape. 'Delaware' is not known to have been introduced to Europe
or Australasia
.
NB 'Delaware I' is the original name given to the hybrid 'Urban' before its commercial release.
American Elm
Ulmus americana, generally known as the American Elm or, less commonly, as the White Elm or Water Elm, is a species native to eastern North America, occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. The American elm is an extremely hardy tree that can...
Ulmus americana cultivar 'Delaware' was originally selected (as tree number 218) from 35,000 seedlings inoculated with the Dutch elm disease
Dutch elm disease
Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...
fungus in USDA trials at Morristown
Morristown, New Jersey
Morristown is a town in Morris County, New Jersey, United States. As of the 2010 United States Census, the town population was 18,411. It is the county seat of Morris County. Morristown became characterized as "the military capital of the American Revolution" because of its strategic role in the...
, New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
.
Pests and diseases
Further disease-resistance trials were conducted by both the USDA and the United States National ArboretumUnited States National Arboretum
The United States National Arboretum is an arboretum in Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service as a division of the Henry A. Wallace Beltsville Agricultural Research Center...
which confirmed the clone had a fair level of resistance to Dutch elm disease. 'Delaware' is susceptible to Elm Yellows
Elm Yellows
Elm Yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts. Elm Yellows, also known as Elm Phloem Necrosis, is very aggressive, with no known cure. Elm Yellows occurs in the Eastern United States and southern Ontario in Canada. It is caused by phytoplasmas which...
, but resistant to the Elm Leaf Beetle Xanthogaleruca luteola
Xanthogaleruca luteola
Xanthogaleruca luteola, commonly known as the Elm Leaf Beetle, is a serious pest of the elm. Indigenous to Europe, it was accidentally introduced to North America. Both the imagines and larvae feed on the emergent leaves of the elm...
.
Cultivation
The original tree, which had been moved to the USDA National ArboretumUnited States National Arboretum
The United States National Arboretum is an arboretum in Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service as a division of the Henry A. Wallace Beltsville Agricultural Research Center...
, Washington, D. C. in 1948, died from unknown causes (probably elm yellows, by some accounts) in 1980, but a clone survives at the Denver Botanic Gardens
Denver Botanic Gardens
The Denver Botanic Gardens is a public botanical garden located in Denver, Colorado in the Cheesman Park neighborhood. The park contains a conservatory, a variety of theme gardens and a sunken amphitheater, which hosts various concerts in the summer...
, as 'Delaware II'. Although propagated for further trials, the tree was never commercially released owing to its poor shape. 'Delaware' is not known to have been introduced to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
or Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
.
Synonymy
- 'Delaware II'.
NB 'Delaware I' is the original name given to the hybrid 'Urban' before its commercial release.
North America
- Brooklyn Botanic GardenBrooklyn Botanic GardenBrooklyn Botanic Garden is a botanical garden in the borough of Brooklyn in New York City. Located near the Prospect Heights, Crown Heights, and Park Slope neighborhoods, the garden includes a number of specialty "gardens within the Garden," plant collections, and the Steinhardt Conservatory,...
http://www.bbg.org/cgi/bgbase/search.cgi, New YorkNew YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
. Acc. no. 980489. - Dawes ArboretumDawes ArboretumThe Dawes Arboretum is a non-profit arboretum located outside of Columbus in Newark, Ohio. As one of the premier public gardens in North America, The Dawes Arboretum has over of plant collections, gardens and natural areas...
http://www.dawesarb.org/collectionsgardens/plant-search.asp, NewarkNewark, OhioIn addition, the remains of a road leading south from the Octagon have been documented and explored. It was first surveyed in the 19th century, when its walls were more apparent. Called the Great Hopewell Road, it may extend to the Hopewell complex at Chillicothe, Ohio...
, OhioOhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
. 1 trees, listed as 'Delaware #2'; no acc. details available. - Denver Botanic GardensDenver Botanic GardensThe Denver Botanic Gardens is a public botanical garden located in Denver, Colorado in the Cheesman Park neighborhood. The park contains a conservatory, a variety of theme gardens and a sunken amphitheater, which hosts various concerts in the summer...
. No details available. - Dominion ArboretumDominion ArboretumThe Dominion Arboretum is located at the Central Experimental Farm of Agriculture and Agri-Food Canada in Ottawa, Ontario, Canada.Originally begun in 1889 the Arboretum covers about 26 ha of rolling land between Prince of Wales Drive, Dow's Lake and the Rideau Canal. Carleton University is located...
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, http://www.agr.gc.ca/sci/arboretum/index_e.php?section=specimens&page=141ulm&PHPSESSID=28c7cb5641bcf4dd8e6dd948ebd359bb. No details available.