American Elm Ulmus americana Linnaeus    Synonyms: Ulmus floridana.
Kingdom Plantae   >   Division Tracheophyta   >   Class Magnoliopsida   >   Order Urticales   >   Family Ulmaceae   >   Genus Ulmus   

Status:

American Elm and Slippery Elm are the two most common elm species in Maryland.

Description:

The overall shape of open-grown American Elm trees is vase-shaped. Slippery Elm tends to have rougher upper leaf surfaces than American Elm, but the two species can be difficult to differentiate on this basis. A better diagnostic tool is the winged fruits, or samaras. The samaras of American Elm usually have a pronounced notch at the tip and are hairy along the margins, whereas the samaras of Slippery Elm do not have a pronounced notch at the tip, are smooth along the margins, and tend to be rounder than American Elm samaras. The bark is also different between the two species: If a piece of bark is sliced with a knife, dark and light layers are seen in the cross section of American Elm, whereas the bark is uniformly reddish brown in cross sections of Slippery Elm.

Relationships:

Various moth species use American Elm as a host plant including American Dagger Moth, Banded Tussock Moth, Pale Beuaty Moth, and Elm Sphinx (Database of World's Lepidopteran Host Plants).

The Mourning Cloak butterfly may use American Elm as a larval host.

The leaf beetle Calligrapha scalaris uses American Elm as a host plant.

The European Elm Bark Beetle and Banded Elm Bark Beetle use this tree as a host. Both are vectors of Dutch Elm Disease, which has decimated elms planted as street trees but has had little effect on forest-grown trees.

There are 79 records in the project database.

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American Elm leaves in Howard Co., Maryland (9/8/2013). Photo by Bill Hubick. (MBP list)

The newly emerged leaves of an American Elm in Talbot Co., Maryland (4/23/2013). Photo by Jim Brighton. (MBP list)

American Elm in Talbot Co., Maryland (4/23/2013). Photo by Jim Brighton. (MBP list)

American Elm growing in Kent Co., Maryland (4/16/2016). Photo by Nancy Martin. (MBP list)

American Elm in Montgomery Co., Maryland (9/2/2016). Photo by Jane Hill. (MBP list)

American Elm seedpods in Howard Co., Maryland (3/28/2016). Determined by Jim Brighton. Photo by Nancy Magnusson. (MBP list)

Seeds of an American Elm in Delaware Co., Ohio (5/8/2005). Photo by Robert Klips. (MBP list)

An American Elm fruit in Harford Co., Maryland (5/16/2018). Photo by Josh Emm. (MBP list)

American Elm in Anne Arundel Co., Maryland (3/7/2011). Photo by Bill Harms. (MBP list)

American Elm flowers in Dane Co., Wisconsin (3/16/2012). Photo by Corey Raimond. (MBP list)

American Elm in Anne Arundel Co., Maryland (3/18/2011). Photo by Bill Harms. (MBP list)

American Elm in Baltimore City, Maryland (4/22/2019). Photo by Kirsten Johnson. (MBP list)

American Elm in Allegany Co., Maryland (4/13/2019). Photo by Jim Brighton. (MBP list)

American Elm in Anne Arundel Co., Maryland (2/24/2011). Photo by Bill Harms. (MBP list)

American Elm in Baltimore Co., Maryland (5/11/2019). (c) samanthaeff, some rights reserved (CC BY-NC). Photo by samanthaeff via iNaturalist. (MBP list)

American Elm in Baltimore Co., Maryland (5/11/2019). (c) samanthaeff, some rights reserved (CC BY-NC). Photo by samanthaeff via iNaturalist. (MBP list)


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