The

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

elm

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, ...

''Ulmus × hollandica'' 'Pioneer' is an American clone arising from the crossing of two European species,

Wych Elm ''Ulmus glabra'' Hudson, the wych elm or Scots elm, has the widest range of the European elm species, from Ireland eastwards to the Urals, and from the Arctic Circle south to the mountains of the Peloponnese and Sicily, where the species reaches i ...

''U. glabra'' (female parent) and

Field Elm ''Ulmus minor'' Mill., the field elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern ...

''U. minor''. Raised by the

USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

station at

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 Del ...

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

, in 1971, 'Pioneer' was released to commerce in 1983.

Description

'Pioneer' is a fast-growing tree distinguished by a dense, globular crown, which as it matures becomes more broad than tall, like its ''U. glabra'' parent, and casting a heavy shade. The leaves are deep green, and similar in shape to the

,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. colouring yellow and red in the fall. The perfect,

apetalous Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usually ...

wind-pollinated flowers appear in early March.

Pests and diseases

The tree's 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 Americas, America ...

, rated 4 out of 5,Heybroek, H. M., Goudzwaard, L, Kaljee, H. (2009). ''Iep of olm, karakterboom van de Lage Landen'' (:Elm, a tree with character of the Low Countries). KNNV, Uitgeverij. is somewhat less than more recent American hybrids, and for this reason the tree was omitted from the elm trial

in 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 ...

conducted by the

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. ...

. 'Pioneer' is also severely damaged by 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 ...

'', sustaining more foliar damage (50%) than any other cultivar in an assessment conducted 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 tri ...

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 institut ...

,McPherson, G. ''et al''. (2008). National elm trial: Initial report from Northern California. ''Western Arborist'', Fall 2009, pp 32-36. and

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 controlle ...

.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. Tolerance of

Elm Yellows Elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts."Elm Yellows." Elmcare.Com. 19 Mar. 2008 . Elm yellows, also known as elm phloem necrosis, is very aggressive, with no known cure. Elm yellows occurs in the ...

in the United States was also found to be poor.Sinclair, W. A., Townsend, 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 The tree's foliage was adjudged "resistant" to Black Spot by the Plant Diagnostic Clinic of the

University of Missouri The University of Missouri (Mizzou, MU, or Missouri) is a public university, public Land-grant university, land-grant research university in Columbia, Missouri. It is Missouri's largest university and the flagship of the four-campus Universit ...

br>

Cultivation

Considered "quite hardy in Saint Paul, Minnesota, Saint Paul", and "definitely a good selection for the Twin Cities (St. Paul and Minnesota) urban forest" although very different in appearance to the

American Elm ''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Flor ...

.Giblin, C. P. & Gillman, J. H. (2006). ''Elms for the Twin Cities: A Guide for Selection and Maintenance.'' University of Minnesota. 'Pioneer' has had a very limited introduction to Europe, featuring in street tree trials in several Dutch cities in the late 1990s. The tree has reputedly been planted in Preston Park,

Brighton Brighton () is a seaside resort and one of the two main areas of the City of Brighton and Hove in the county of East Sussex, England. It is located south of London. Archaeological evidence of settlement in the area dates back to the Bronze A ...

, and along Tisbury Road,

Hove Hove is a seaside resort and one of the two main parts of the city of Brighton and Hove, along with Brighton in East Sussex, England. Originally a "small but ancient fishing village" surrounded by open farmland, it grew rapidly in the 19th cen ...

, but does not feature in the NCCPG National Elm Collection held there. File:cathedral - regal - pioneer - urban - laevis - den haag.jpg, Elm cultivars, Netherlands; 'Pioneer' 3rd from left File:Pioneer Elm in Toronto.jpg, 'Pioneer' in Toronto (May 2016)

Accessions

North America

*Bartlett Tree Experts, US. Acc. nos. 85–0195, 85–0199 *

Denver Botanic Gardens The Denver Botanic Gardens is a public botanical garden located in the Cheesman Park neighborhood of Denver, Colorado. The park contains a conservatory, a variety of theme gardens and a sunken amphitheater, which hosts various concerts in the su ...

, US. No acc. details. *

Dawes Arboretum The Dawes Arboretum is a nonprofit arboretum located in Newark, Ohio. It includes nearly of plant collections, gardens and natural areas. The site includes approximately 12 miles (19 km) of hiking trails and roadways for a four-mile (6&nbs ...

Newark Newark most commonly refers to: * Newark, New Jersey, city in the United States * Newark Liberty International Airport, New Jersey; a major air hub in the New York metropolitan area Newark may also refer to: Places Canada * Niagara-on-the ...

, US. 1 tree (2022), accession no. D1986-0021.001''Ulmus'' × ''hollandica'' 'Pioneer', The Dawes Arboretum, Arboretum Explorer (Newark, Ohio) dawesarb.arboretumexplorer.org
/ref> *

Dominion Arboretum The Dominion Arboretum (french: Arboretum du Dominion) is an arboretum part of the Central Experimental Farm of Agriculture and Agri-Food Canada in Ottawa, Ontario, Canada. Originally begun in 1889, the Arboretum covers about of rolling land ...

Ottawa Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core ...

, Canada. No acc. details. *

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 t ...

, US. Acc. no. 90–58 *

New York Botanical Garden The New York Botanical Garden (NYBG) is a botanical garden at Bronx Park in the Bronx, New York City. Established in 1891, it is located on a site that contains a landscape with over one million living plants; the Enid A. Haupt Conservatory, ...

, US. Acc. no. 955/97 *

Smith College Smith College is a Private university, private Liberal arts colleges in the United States, liberal arts Women's colleges in the United States, women's college in Northampton, Massachusetts. It was chartered in 1871 by Sophia Smith (Smith College ...

, US. Acc. no. 5603. *

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 University ...

Arboretum, US. One tree. Acc. no. 1990013 * U S National Arboretumbr>

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

, US. Acc. no. 76233.

Europe

*Grange Farm Arboretum, Sutton St. James, Spalding,

Lincolnshire Lincolnshire (abbreviated Lincs.) is a 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-west, Leicestershire ...

, UK. Acc. No. 544

Nurseries

North America

*Bailey Nurserie

St. Paul, Minnesota, St. Paul,

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 to ...

, US. *ForestFar

Williams, Oregon, Williams,

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, US. *J. Frank Schmidt & Son Co

Boring, Oregon, Boring,

, 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 communi ...

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, Hermann,

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

, 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.

Europe

*Batouwe Boomkwekerij B.V.

Dodewaard Dodewaard is a village in the Netherlands, Dutch province of Gelderland. It is a part of the municipality of Neder-Betuwe, and lies about 7 km south of Wageningen. Dodewaard was a separate municipality until 2002, when it became a part of K ...

, Netherlands. *Noordplan

Glimmen Glimmen is a village in the northeastern Netherlands. It is located in the municipality of Groningen, about 10 kilometres from the city. It had a population of around 1,342 in 2021. The river Drentsche Aa flows past the village, nearby the ''Huis ...

, Netherlands. *Van Den Berk (UK) Ltd.

London, UK *Westerveld Boomkwekerij B.

Opheusden Opheusden is a village in the Dutch province of Gelderland. It is a part of the municipality of Neder-Betuwe, and lies some 5 km south-west of Wageningen. Opheusden (or "Heusden", as it was known then) was a separate municipality until 1818, ...

, Netherlands.

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''. {{DEFAULTSORT:Ulmus x hollandica 'Pioneer' Dutch elm cultivar Ulmus articles with images Ulmus