''Ulmus'' 'Patriot

is a hybrid

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...

raised by the

United States National Arboretum The United States National Arboretum is an arboretum in northeast Washington, D.C., operated by the United States Department of Agriculture's Agricultural Research Service. It was established in 1927 by an act of Congress after a campaign by USDA ...

in 1980. Derived from a crossing of the American hybrid 'Urban' (female parent) with the Wilson's Elm (now treated as

Japanese Elm Japanese elm is a common name for several plants and may refer to: * ''Ulmus davidiana'' var. ''japonica'' *''Zelkova serrata ''Zelkova serrata'' (Japanese zelkova, Japanese elm or keyaki or keaki; ja, 欅 (ケヤキ) keyaki /槻 (ツキ) tsu ...

''U. davidiana'' var. ''japonica'') cultivar 'Prospector', 'Patriot' was released to commerce, free of patent restrictions, in 1993.

Tested in the US National Elm Trial coordinated by

Colorado State University Colorado State University (Colorado State or CSU) is a Public university, public Land-grant university, land-grant research university in Fort Collins, Colorado. It is the flagship university of the Colorado State University System. Colorado S ...

'Patriot' averaged a survival rate of 85% after 10 years.

Description

The tree develops an upsweeping crown, ultimately adopting a narrow vase-shape. The leaves are slightly leaf shape, obovate, with doubly serrate margins and typically acuminate apices; they are of an average size for the genus, < 10 cm long by 7.5 cm broad, glossy dark green turning yellow in autumn.Santamour, J., Frank, S. & Bentz, S. (1995). Updated checklist of elm (Ulmus) cultivars for use in North America. ''Journal of Arboriculture'', 21:3 (May 1995), 121–131. International Society of Arboriculture, Champaign, Illinois, US

/ref> The perfect flower, perfect, apetalous wind-pollinated flowers appear in March. Flowering usually begins when the tree is aged six years. Growth is vigorous; specimens in the USDA trials reaching a height of over 13 m (43 ft) and a spread of nearly 8 m (25 ft) after only 13 years. In an assessment at

U C Davis The University of California, Davis (UC Davis, UCD, or Davis) is a public land-grant research university near Davis, California. Named a Public Ivy, it is the northernmost of the ten campuses of the University of California system. The instit ...

as part of the

National Elm Trial The National Elm Trial was an American volunteer effort to evaluate a range of newly developed elm cultivars as replacements for elms destroyed by Dutch elm disease. The Colorado State University College of Agricultural Sciences coordinated the tr ...

, 'Patriot' increased in height by almost 1.5 m and

d.b.h. Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements. Tree trunks are measured at the height of an adult's breast, ...

by 2.5 cm per annum.McPherson, G. ''et al''. (2008). National elm trial: Initial report from Northern California. ''Western Arborist'', Fall 2009, pp 32-36.
Image:Ulmus 'Patriot' leaves.jpg, 'Patriot' leaves

Pests and diseases

'Patriot' was found to have a very high resistance to

Dutch elm disease Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into America, Europe ...

(DED) in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, exhibiting 100% survival seven years after inoculation with the causal pathogen. Tolerance of the elm leaf beetle ''

Xanthogaleruca luteola ''Xanthogaleruca luteola'', commonly known as the elm-leaf beetle, is a beetle species in the family Chrysomelidae that is native to Europe but invasive in other parts of the world.http://cisr.ucr.edu/elm_leaf_beetle.html - Center for Invasive Sp ...

'' is generally regarded as only moderate, although specimens grown at the aforementioned trials at

were among those cultivars least affected; resistance to

Japanese Beetle The Japanese beetle (''Popillia japonica'') is a species of scarab beetle. The adult measures in length and in width, has iridescent copper-colored elytra and a green thorax and head. It is not very destructive in Japan (where it is control ...

is poor.Brady, C., Condra, J., & Potter, D. (2008) Resistance of Landscape-suitable Elm (Ulmus spp.) Cultivars to Japanese Beetle, Leaf Miners, and Gall Makers. ''2008 Research Report, Nursery & Landscape Program'', 15–16. University of Kentucky. When grown for 11 years among hundreds of infected American Elms in

Delaware Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent ...

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

, the clone showed no signs of susceptibility to Elm Yellowsbr>
ref name=Townsend>Townsend, A. M. & Douglass, L. W. (2004). Evaluation of elm clones for tolerance of Dutch elm disease. ''Journal of Arboriculture'' 21(3). International Society of Arboriculture, Champaign, IL. however when tested by deliberate infection, tolerance was found to be poor.Sinclair, W. A., Townend, A. M., Griffiths, H. M., & Whitlow, T. H. (2000). Responses of six Eurasian Ulmus cultivars to a North American elm yellows phytoplasma. ''Plant disease'', Vol. 84, No.12, 1266–1270. American Phytopathological Society, St. Paul, MN

Cultivation

The tree performs best in moist but well-drained soils, but will tolerate alkaline ground and salt

In trials by

Northern Arizona University Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona. It was founded in 1899 as the final public university established in the Arizona Territory, 13 years before Arizona was admitted as the 48th state. ...

in the hot and arid climate of Holbrook, eastern

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

br>
it did not perform as well as Ulmus 'Frontier', 'Frontier' and 'Regal', but not as badly as others such as 'New Horizon' and 'Sapporo Autumn Gold'. In the cooler climes of

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over t ...

, it was recommended for every forester's 'Top Ten' list of urban trees.Giblin, C. P. & Gillman, J. H. (2006). ''Elms for the Twin Cities: A Guide for Selection and Maintenance.'' University of Minnesota. 'Patriot' is extremely cold hardy; in artificial freezing tests at the Morton Arboretum Shirazi, A. M. & Ware, G. H. (2004). ''Evaluation of New Elms from China for Cold Hardiness in Northern Latitudes''. International Symposium on Asian Plant Diversity & Systematics 2004,

Sakura A cherry blossom, also known as Japanese cherry or sakura, is a flower of many trees of genus ''Prunus'' or ''Prunus'' subg. ''Cerasus''. They are common species in East Asia, including China, Korea and especially in Japan. They generally ...

, Japan. the

LT50 LT50 is the median Lethal Time (time until death) after exposure of an organism to a toxic substance or stressful condition. LT50 is commonly used in toxicology studies to quantify amount of a stressor necessary to kill an organism. LT50 can be use ...

(temp. at which 50% of tissues die) was found to be - 38 °C. Propagation from softwood cuttings is reputedly easy; taken in mid-May, treated with a 3000 ppm IBA rooting hormone and placed under mist, < 95% should root in less than four weeks. However, commercial propagation is commonly by grafting onto a Siberian Elm '' Ulmus pumila'' rootstock. As height increase can rapidly outstrip stem width, lopping the stem above a leaf node at breast height and vertically training the new leader is recommended to create a more stable structure. The tree is currently being evaluated in the

br>
coordinated by

. 'Patriot' was introduced to the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

and the UK in 2008,Brookes, A. H. (2020). ''Great Fontley Elm Trial, 2020 Report''. Butterfly Conservation, Lulworth, England. and to Italy in 2011 by the

Istituto per la Protezione delle Piante The Istituto per la Protezione delle Piante (IPP), or 'Institute of Plant Protection', is part of the Food Department of the Consiglio Nazionale delle Ricerche (CNR; "Italian National Research Council"), an Italian government organization with the ...

Florence Florence ( ; it, Firenze ) is a city in Central Italy and the capital city of the Tuscany region. It is the most populated city in Tuscany, with 383,083 inhabitants in 2016, and over 1,520,000 in its metropolitan area.Bilancio demografico ...

Accessions

North America

Arnold Arboretum The Arnold Arboretum of Harvard University is a botanical research institution and free public park, located in the Jamaica Plain and Roslindale neighborhoods of Boston, Massachusetts. Established in 1872, it is the oldest public arboretum in ...

, US. Acc. no. 136–98. *Bartlett Tree Experts, US. Acc. nos. 2001–252/3/4, 2001–492/3, 2003–965, 2003–1007/8. * Brenton Arboretum, US. 5 trees, acquired 2009. Acc. no. not known. *

Chicago Botanic Garden The Chicago Botanic Garden is a living plant museum situated on nine islands in the Cook County Forest Preserves. It features 27 display gardens in four natural habitats: McDonald Woods, Dixon Prairie, Skokie River Corridor, and Lakes and Shor ...

, US. 1 tree, in the Parking Lots. *

Holden Arboretum The Holden Arboretum, in Kirtland, Ohio, is one of the largest arboreta and botanical gardens in the United States, with more than , including devoted to collections and gardens. Diverse natural areas and ecologically sensitive habitats make up ...

, US. Acc. nos. 00–125, 2001–154. *

Morton Arboretum The Morton Arboretum, in Lisle, Illinois, United States, is a public garden, and outdoor museum with a library, herbarium, and program in tree research including the Center for Tree Science. Its grounds, covering 1,700 acres (6.9 square kilometres ...

, US. Acc. no. 122–2001. *North Central Region Plant Introduction Station, ARS,

Ames, Iowa Ames () is a city in Story County, Iowa, United States, located approximately north of Des Moines in central Iowa. It is best known as the home of Iowa State University (ISU), with leading agriculture, design, engineering, and veterinary me ...

, US. Acc. no. PI566597 * U S National Arboretum, Washington, D.C., US. Acc. nos. 72141, 66830. *

University of Idaho The University of Idaho (U of I, or UIdaho) is a public land-grant research university in Moscow, Idaho. It is the state's land-grant and primary research university,, and the lead university in the Idaho Space Grant Consortium. The Universit ...

Arboretum, US. Two trees. Acc. no. 2000090.

Europe

Grange Farm Arboretum The Grange Farm Arboretum is a small private arboretum comprising 3 hectares accommodating over 800 trees, mostly native and ornamental species or cultivars, notably oaks, ashes, walnuts and elms, growing on a calcareous loam.Ostler, J. (2009) ...

Lincolnshire Lincolnshire (abbreviated Lincs.) is a Counties of England, county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-we ...

, UK. Acc. no. 505. *

, Italy. 2 small (<0.4 m) plants (2011). *

Royal Botanic Garden Edinburgh The Royal Botanic Garden Edinburgh (RBGE) is a scientific centre for the study of plants, their diversity and conservation, as well as a popular tourist attraction. Founded in 1670 as a physic garden to grow medicinal plants, today it occupies ...

, UK. Acc. no. 20110001.

Nurseries

North America

*J. Frank Schmidt & So

Boring, Oregon Boring is an unincorporated community in Clackamas County, Oregon, United States. It is located along Oregon Route 212 in the foothills of the Cascade mountain range, approximately southeast of downtown Portland, and northeast of Oregon City. ...

, US. *Johnson's Nurser

Menomonee Falls Menomonee Falls is a village in Waukesha County, Wisconsin, United States, and is part of the Greater Milwaukee area. The population was 35,626 at the 2010 census, making it the most populous village in Wisconsin. It is the fourth largest commu ...

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

, US. *Pea Ridge Fores

Hermann, Missouri, US. *Sun Valley Garden Centr

Eden Prairie Eden Prairie is a city southwest of downtown Minneapolis in Hennepin County and the 16th-largest city in the State of Minnesota, United States. As of the 2020 census, it has a population of 64,198. The city is adjacent to the north bank of th ...

, US.

References

External links

*http://www.extension.iastate.edu/Publications/SUL4.pdf Summary, inc. photographs, of elm cultivars resistant to Dutch elm disease available in the United States. *https://web.archive.org/web/20030413074605/http://fletcher.ces.state.nc.us/programs/nursery/metria/metria11/warren/elm.htm Warren, K., J. Frank Schmidt & Son Co. (2002). ''The Status of Elms in the Nursery Industry in 2000''. {{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed Hybrid elm cultivar Ulmus articles with images Ulmus