?American Elm
Ulmus americana (American Elm)
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Urticales Family: Ulmaceae Genus: Ulmus Species: U. americana
Binomial name
Ulmus americana L.

The American Elm Ulmus americana is a species of elm native to eastern North America, occurring from Nova Scotia west to southeast Saskatchewan, and south to Florida and central Texas. It is also sometimes known as White Elm or American White Elm. It is an extremely hardy tree that can withstand harsh winters (min. temperature of -42 Cel.), even in northern and central British Columbia, Alberta and Saskatchewan, where they have been extensively planted as ornamental trees in cities across these Canadian provinces. Healthy trees potentially can live for hundreds of years. Download high resolution version (633x700, 120 KB)Ulmus americana (American Elm) This tree at Longwood Gardens was planted in the 1930s and is the last American elm in the gardens (the others having been lost to Dutch Elm Disease). ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) †Rhyniophyta - rhyniophytes †Zosterophyllophyta - zosterophylls Lycopodiophyta - clubmosses †Trimerophytophyta - trimerophytes Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also called angiosperms) are the dominant and most familiar group of land plants. ... Orders See text. ... The Urticales are an order of dicotyledons in the Cronquist system of classification for flowering plants, including the following families: Barbeyaceae Cannabaceae (hemp family) Cecropiaceae Moraceae (mulberry family) Physenaceae Ulmaceae (elm family) Urticaceae (nettle family) These range from small herbaceous plants to large trees, blooming from the late spring to... Genera Celtis - Hackberries Planera - Water-elm Ulmus - Elms Zelkova - Zelkovas Ulmaceae is a family of flowering plants that includes elms, hackberries and zelkovas. ... Species See text. ... In biology, binomial nomenclature is the formal method of naming species. ... Carolus Linnaeus Carl Linnaeus, also known after his ennoblement as , (May 23, 1707 – January 10, 1778), was a Swedish botanist, physician and zoologist[1] who laid the foundations for the modern scheme of nomenclature. ... Species See text. ... World map showing North America A satellite composite image of North America. ... Motto: Munit Haec et Altera Vincit (Latin: One defends and the other conquers) Official languages None (English,French,Gaelic) Flower Trailing arbutus Tree Red Spruce Bird Osprey Capital Halifax Largest city Halifax Lieutenant-Governor Mayann E. Francis Premier Rodney MacDonald (PC) Parliamentary representation  - House seat  - Senate seats 11 10 Area... Motto: Multis E Gentibus Vires (Latin: From many peoples, strength) Official languages English Flower Western Red Lily Tree Paper Birch Bird Sharp-tailed Grouse Capital Regina Largest city Saskatoon Lieutenant-Governor Gordon Barnhart Premier Lorne Calvert (NDP) Parliamentary representation  - House seat  - Senate seats 14 6 Area Total  - Land  - Water  (% of... This article or section does not cite its references or sources. ... Official language(s) See: Languages of Texas Capital Austin Largest city Houston Area  Ranked 2nd  - Total 268,581 sq mi (695,622 km²)  - Width 773 miles (1,244 km)  - Length 790 miles (1,270 km)  - % water 2. ... Motto: Splendor Sine Occasu (Latin: Splendour without diminishment) Official languages English de facto (none stated in law) Flower Pacific dogwood Tree Western Redcedar Bird Stellers Jay Capital Victoria Largest city Vancouver Lieutenant-Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Parliamentary representation  - House seat  - Senate seats 36 6 Area... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Multis E Gentibus Vires (Latin: From many peoples, strength) Official languages English Flower Western Red Lily Tree Paper Birch Bird Sharp-tailed Grouse Capital Regina Largest city Saskatoon Lieutenant-Governor Gordon Barnhart Premier Lorne Calvert (NDP) Parliamentary representation  - House seat  - Senate seats 14 6 Area Total  - Land  - Water  (% of...

Description

The American Elm is a deciduous tree, sometimes growing up to 30 m [100 ft] tall with a trunk up to 1.2 m [4 ft] in diameter. The crown forms a high, spreading canopy with open air space beneath. The leaves are alternate, 7-15 cm long, with double-serrate margins and an oblique base. The tree is hermaphroditic, having perfect flowers, i.e. with both male and female parts, and is therefore capable of self-pollination. The flowers are small, purple-brown and, being wind-pollinated, have no petals; they emerge in early spring before the leaves. The fruit is a flat samara 2 cm long and 1.5 cm broad, with a circular wing surrounding the single 4-5 mm seed; like the closely related European White Elm, U. laevis, the flowers and seeds are borne on 1-3 cm long stems. The American Elm reaches sexual maturity at around 15 years of age and is unique within the genus in being tetraploid, i.e. having double the usual number of chromosomes. Deciduous means temporary or tending to fall off (deriving from the Latin word decidere, to fall off). ... The coniferous Coast Redwood, the tallest tree species on earth. ... The leaves of a Beech tree A leaf with laminar structure and pinnate venation In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... In zoology, a hermaphrodite is a species that contains both male and female sexual organs at some point during their lives. ... A perfect flower, in botany, is a hermaphroditic flower with both stamens and an ovary. ... Wildflowers A flower is the reproductive organ of those plants classified as angiosperms ( flowering plants; Division Magnoliophyta). ... Fruit stall in Barcelona, Spain. ... Maple samara or key A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. ... A ripe red jalapeno cut open to show the seeds For other uses, see Seed (disambiguation). ... Binomial name Ulmus laevis Pall. ... Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms contain more than one copy (ploidy) of their chromosomes. ...

Dutch Elm Disease

The American elm has been seriously affected by an introduced fungal disease, Dutch elm disease (DED), with heavy mortality in most of the range and in many areas outside of the natural range as far west as California. However, DED has had little impact in Florida and has not spread to the northernmost areas of cultivation, such as most of Alberta and British Columbia. Divisions Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Deuteromycota A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... Contagious redirects here. ... Branch death, or Flagging, at multiple locations in the crown of a diseased elm. ... This article is becoming very long. ... This article or section does not cite its references or sources. ... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Splendor Sine Occasu (Latin: Splendour without diminishment) Official languages English de facto (none stated in law) Flower Pacific dogwood Tree Western Redcedar Bird Stellers Jay Capital Victoria Largest city Vancouver Lieutenant-Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Parliamentary representation  - House seat  - Senate seats 36 6 Area...

Dutch elm disease has ravaged the American elm, causing catastrophic die-offs in cities across the range. It is an extraordinarily efficient fungal disease that causes the trees to wither and eventually to die, by blocking the circulation of water and nutrients through their inner bark. The disease was accidentally introduced into North America in 1930, after it already had destroyed populations of Dutch elm hybrids in Europe and thus gained its name. Infection occurs when an elm bark beetle vectors the fungus from an infected tree and then burrows into the living tissue of a healthy tree. Once this disease infected one tree on a street, other American elm trees close to it would die quickly because the fungus would infect them via the roots through root grafts that the trees had formed underground; if an infected tree had root grafts with an adjacent tree, the fungus could spread easily from one tree to the other directly through the roots, removing the need for the fungus to be vectored by another beetle. There still are many American Elms in the woods and occasionally in the suburbs, but in cities, the ones that survived are generally those that are isolated from other elms. Examples of this are Central Park and Tompkins Square Park in New York City, where stands of several large elms originally planted by Frederick Law Olmstead survive due to isolation from neighboring areas in New York where there were massive die-offs. In historic areas of Philadelphia, Pennsylvania there are also a few surviving, mature American elms standing -- notably in Independence Square and the Quadrangle at the University of Pennsylvania-- and at the nearby campuses of Haverford College and Swarthmore College. Branch death, or Flagging, at multiple locations in the crown of a diseased elm. ... Divisions Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Deuteromycota A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... A Central Park landscape Central Park ( ) is a large public, urban park (843 acres or 3. ... Tompkins Square Park is a 10. ... Nickname: Big Apple, City that never Sleeps image_skyline = Top_of_Rock_Cropped. ... Frederick Law Olmsted (April 27, 1822–August 28, 1903) was a United States landscape architect, famous for designing many well known urban parks, including Central Park in New York, New York, the oldest coordinated system of public parks and parkways in Buffalo, New York, Mount_Royal_Park in Montreal, the Metropolitan... Nickname: City of Brotherly Love, Philly, the Quaker City Motto: Philadelphia maneto (Let brotherly love continue) Location in Pennsylvania Coordinates: Country United States State Pennsylvania County Philadelphia Founded October 27, 1682 Incorporated October 25, 1701 Mayor John F. Street (D) Area    - City 369. ... The University of Pennsylvania (or Penn[3][4]) is a private, nonsectarian research university located in Philadelphia, Pennsylvania. ... Haverford College is a private, coeducational liberal arts college located in Haverford, Pennsylvania, a suburb of Philadelphia. ... Swarthmore College is a private liberal arts college in the United States with an enrollment of about 1450 students. ...

The American elm's biology in many ways has spared it from obliteration by the disease, in contrast to what happened to the American chestnut with the chestnut blight. The elm's seeds are wind-dispersed, and the tree grows quickly and begins bearing seeds at a young age. It grows well along roads or railroad tracks, and in abandoned lots and other disturbed areas. Elms have been able to survive and reproduce in areas where the blight eliminated old trees, although most of these new elms succumb to the blight at a relatively young age. There is hope that these elms will preserve the genetic diversity of the original population, and that they will eventually hybridize with resistant varieties that are either developed or occur naturally. Binomial name Castanea dentata (Marsh. ...

In some areas still not yet populated by the Dutch Elm disease-carrying Elm bark beetle, the American Elm continues to thrive, particularly in most of Alberta and in British Columbia. It is reliable and recommended in places such as Calgary and Edmonton in Alberta. In fact, the province of Alberta has the largest number of DED-free American elms in the world. Aggressive measures are being taken to combat the spread of DED into Alberta, especially after a tree was found to have DED in southeastern Alberta in 1998. (the tree was immediately destroyed and this was an isolated case, as no other trees were affected) A smaller beetle, the European bark beetle, is also known to carry the disease. Although the European bark beetle is known to have been found across southern and central Alberta, they apparently do not seem to be carrying the disease. Genera See text. ... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Splendor Sine Occasu (Latin: Splendour without diminishment) Official languages English de facto (none stated in law) Flower Pacific dogwood Tree Western Redcedar Bird Stellers Jay Capital Victoria Largest city Vancouver Lieutenant-Governor Iona Campagnolo Premier Gordon Campbell (BC Liberal) Parliamentary representation  - House seat  - Senate seats 36 6 Area... Calgary is a city in the province of Alberta, Canada. ... Edmonton is the capital of the Canadian province of Alberta, situated in the north central region of the province, an area with some of the most fertile farm land on the prairies. ... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total...

Some cities such as Kansas City, Missouri had used mostly American elms in planting its city streets, and had some of the best-shaded residential streets in the nation until the disease almost obliterated these plantings in the late 1960s and early 1970s. Some American cities still have some survivors, but generally this species requires frequent "checkups" by caretakers for beetles and DED infection. (The National Park Service often checks up on the hundreds of elm trees under its care in the Washington D.C. area for signs of illness.) Nickname: City of Fountains or Heart of America Location in Jackson, Clay, Platte, and Cass Counties in the state of Missouri. ... The National Park Service (NPS) is the United States federal agency that manages all National Parks, many National Monuments, and other conservation and historical properties with various title designations. ... Aerial photo (looking NW) of the Washington Monument and the White House in Washington, DC. Washington, D.C., officially the District of Columbia (also known as D.C.; Washington; the Nations Capital; the District; and, historically, the Federal City) is the capital city and administrative district of the United...

Attempts have been made over the last few decades, with some success, to breed disease-resistant American elm cultivars. Selections that have been made available to the public include 'Valley Forge', 'New Harmony,' 'Princeton,' 'Jefferson,' and a set of six different clones collectively known as 'American Liberty.' The United States National Arboretum released the Valley Forge and New Harmony varieties to the public in 1996, after screening tests performed in 1992-93 showed each of them to have unusually high levels of resistance to DED. The Princeton variety has been in occasional cultivation since the 1920's, and it gained renewed attention after its performance in the same screening test showed it also to have a high degree of DED resistance. A later test performed in 2002-2003 confirmed the resistance of these same three varieties and also showed the variety 'Jefferson' to have high resistance to DED. The Jefferson elm was released to wholesale nurseries in 2004 and will become increasingly available for planting. Thus far the plantings of these varieties generally appear to be successful. In 2005, 90 Princeton elms were planted near the White House and to date are healthy and thriving. This Osteospermum Pink Whirls is a successful cultivar. ... The United States National Arboretum is an arboretum in Washington D.C., owned by the United States Department of Agriculture. ... North façade of the White House, seen from Pennsylvania Avenue. ...

Fungicidal injections can be administered by a qualified arborist to valuable American Elms to prevent the trees from becoming infected, or to fight the disease once present. Correctly applied, such a systemic treatment can be effective for two or three years.

Cultivation and uses

In years past, it was used widely as a shade tree and street tree because of its graceful, arching, vase-like growth form and its tolerance of stress. Furthermore, the cross-grained wood gives a level of strength to the branches that resists easy breaking. It has been planted beyond its range as far north as central Alberta, and south to Lake Worth, Florida. It survives low desert heat at Phoenix, Arizona. A tree trunk as found at the Veluwe, The Netherlands Wood is derived from woody plants, notably trees but also shrubs. ... Motto: Fortis et liber (Latin: Strong and free) Official languages English (see below) Flower   Wild rose Tree Lodgepole Pine Bird Great Horned Owl Capital Edmonton Largest city Calgary Lieutenant-Governor Norman Kwong Premier Ralph Klein (PC) Parliamentary representation  - House seat  - Senate seats 28 6 Area Total  - Land  - Water  (% of total... Lake Worth is a city located in Palm Beach County, Florida, named for General William J. Worth, who led U.S. forces during the Second Seminole War. ... This article or section does not cite its references or sources. ... Nickname: Valley of the Sun Location in Maricopa County and the state of Arizona Coordinates: Country United States State Arizona Counties Maricopa Incorporated February 25, 1881 Mayor Phil Gordon (D) Area    - City 1,230. ...

Princeton Elm, aged 6 years, Hampshire, England.

Introductions across the Atlantic rarely prospered, even before the outbreak of Dutch elm disease. In the UK, it was noted in the 19th century that the foliage of American elms was far more prone to insect damage than native elms. Examples are still to be found at the Sir Harold Hillier Gardens and in the NCCPG elm collection held by Brighton and Hove City Council, which also includes the cultivars 'Beeb's Weeping' and 'Exhibition'. The cultivar 'Princeton' was made commercially available in 2002, and has been selected by HRH The Prince of Wales to form an avenue from his residence Highgrove House to the garden boundary. Image File history File linksMetadata Download high-resolution version (1161x1791, 2901 KB) Photo taken by author, July 2006 File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): American Elm Metadata This file contains additional information, probably added from the... Image File history File linksMetadata Download high-resolution version (1161x1791, 2901 KB) Photo taken by author, July 2006 File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): American Elm Metadata This file contains additional information, probably added from the... The Atlantic Ocean is Earths second-largest ocean, covering approximately one_fifth of its surface. ... Branch death, or Flagging, at multiple locations in the crown of a diseased elm. ... The Sir Harold Hillier Gardens are claimed to accommodate the worlds largest arboretum comprising 75 hectares filled with over 42,000 trees and shrubs, notably the collection of camellia, magnolia and rhododendron. ... The National Council for the Conservation of Plants and Gardens (NCCPG) was founded as a registered charity in 1978 to combine the talents of botanists, horticulturalists and conservationists with the dedication of keen amateur and professional gardeners, in order to: encourage the propagation and conservation of endangered garden plants in... Brighton and Hove is a city on the south coast of England. ... The eldest son of the reigning monarch of Great Britain is traditionally invested with the title of Prince of Wales. ... Highgrove is the country home of HRH The Prince of Wales, in Gloucestershire. ...

Ecology

American elm is primarily found on bottomlands and floodplains. In hillier terrain, such as the Appalachian Mountains, it prefers to grow along streams. In the United States, it is a major member of four cover types: Black Ash-American Elm-Red Maple; Silver Maple-American Elm; Sugarberry-American Elm-Green Ash; and Sycamore-Sweetgum-American Elm. The first two of these types also occur in Canada.[1] Some hilltops near Témiscaming, Quebec have a Sugar Maple-Ironwood-American Elm cover type. A rainy day in the Great Smoky Mountains, Western North Carolina The Appalachian Mountains (French: les Appalaches) are a vast system of North American mountains, partly in Canada, but mostly in the United States, forming a zone, from 100 to 300 miles wide, running from Newfoundland and Labrador, Canada, 1... Binomial name Fraxinus nigra Marsh Fraxinus nigra, the Black Ash, is a species of ash which occurs in the northeastern United States and much of eastern Canada, from Newfoundland west to southern Manitoba, and south to Illinois and northern Virginia. ... Binomial name Acer rubrum L. Red Maple (Acer rubrum) is also known as Swamp Maple or Soft Maple. ... Binomial name Acer saccharinum L. The Silver Maple (Acer saccharinum) is a species of maple native to the eastern United States and adjacent parts of southeast Canada. ... Species See text Hackberry Celtis is a genus of about 60-70 species of deciduous trees widespread in warm temperate regions of the Northern Hemisphere, in southern Europe, southern and eastern Asia, and southern and central North America, and south to central Africa. ... Binomial name Fraxinus pennsylvanica Marsh. ... Binomial name Platanus occidentalis L. The American sycamore (Platanus occidentalis), also known as American plane and Buttonwood, is one of the species of Platanus native to North America, where it is often just called Sycamore. ... Binomial nomenclature Liquidambar styraciflua American Sweetgum (Liquidambar styraciflua), also known as Redgum is a deciduous tree in the sweetgum genus, native to warm temperate areas of eastern North America. ... Témiscaming is a town located at the south end of Lake Temiscaming on the upper Ottawa River in the Témiscamingue Regional County Municipality of western Quebec. ... Motto: Je me souviens (French: I remember) Official languages French Flower Blue Flag Iris (Iris versicolor Linné) Tree Yellow Birch Bird Snowy Owl Capital Quebec City Largest city Montreal Lieutenant-Governor Lise Thibault Premier Jean Charest (PLQ) Parliamentary representation  - House seat  - Senate seats 75 24 Area Total  - Land  - Water  (% of... Binomial name Acer saccharum Marshall The Sugar Maple Acer saccharum is a prominent tree in the hardwood forests of eastern North America. ...

References

• Brown, Jean-Louis. (1981). Les forêts du Témiscamingue, Québec: écologie et photo-interprétation. Laboratoire d'écologie forestière, Université Laval, Québec.
• Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. pp 1848-1929. Private publication. [2]
• Townsend, A. M., Bentz, S. E., and Douglass L. W. (2005). Evaluation of 19 American Elm Clones for Tolerance to Dutch Elm Disease. Journal of Environmental Horticulture, March 2005, Horticultural Research Institute, Washington, D.C.

External links

• Saving the American Elm, by Bruce Carley
• Republic of Shade: New England and the American Elm, by Thomas J. Campanella
• USDA Plant Guide: American Elm
• Flora of North America, Profile and map: U. americana RangeMap:
• Ulmus americana images at bioimages.vanderbilt.edu
• 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.