American Elm (White Elm, Gray Elm, Water Elm)
Kingdom: Plantae, Division: Tracheophyta, Class: Equisetopsida, Order: Rosales, Family: Ulmaceae, Genus: Ulmus, Species: Ulmus americana · Ulmaceae (Elm family) · Simple deciduous leaf
Species
Ulmus americana
Leaf Type
Simple deciduous leaf
Family
Ulmaceae (Elm family)
Shape
Oblanceolate to elliptical with an asymmetrical base
Size
Approximately 2 to 3 inches long in this pressed specimen, while typical mature leaves on living trees range from 3 to 6 inches long.
Margin
Doubly serrate with sharp teeth
Arrangement
Alternate arrangement along the twig
Rarity
Common, though wild populations have faced significant decline due to Dutch elm disease.
Color & Pattern
Medium to dark green upper surface with a lighter green underside. The color is uniform and typical of a healthy mature summer leaf.
Venation Pattern
Pinnate venation with very straight, prominent parallel side veins extending to the marginal teeth.
Texture & Surface
Slightly rough or scabrous on the upper surface, with minor pubescence along the veins on the lower surface.
Description
The American Elm is a large, graceful deciduous tree historically renowned for its signature vase-like or umbrella-like canopy and arching branches that once formed majestic green tunnels over American streets. The leaves are characteristically asymmetrical at the base, a hallmark of the elm family, with deeply grooved veins and a rough texture. In autumn, the foliage turns a pleasant shade of yellow before dropping.
Key Features
Unequal (asymmetrical) leaf base where one side of the blade joins the petiole lower than the other; doubly serrate margins; prominent straight parallel lateral veins; papery texture when pressed.
Habitat
Found primarily in rich bottomland forests, along riverbanks, floodplains, and moist uplands. It prefers deep, rich, moist soils and moderate to full sun exposure.
Geographic Range
Native to eastern North America, stretching from Nova Scotia west to Alberta, and south to Florida and Texas.
Condition Notes
Good condition as a pressed herbarium specimen. The blade is intact, showing no major insect holes, galls, or chlorosis.
Interesting Facts
The American Elm was once the quintessential shade tree lining urban avenues across North America. Unfortunately, the introduction of Dutch elm disease, a fungal pathogen spread by elm bark beetles, decimated millions of urban and wild trees during the 20th century.
Medicinal & Uses
The inner bark of the slippery elm (a close relative) is well-known for medicinal mucilage, but American elm inner bark has also been used historically for soothing teas and poultices. Widely planted in restored urban forestry programs due to newly developed disease-resistant cultivars.
Ecological Role
Provides critical nesting habitat and food for numerous bird species and mammals. Serves as a larval host plant for several butterfly species, including the question mark and comma butterflies.
Similar Species
Slippery Elm (Ulmus rubra), which has rougher, larger leaves that feel like sandpaper, and Winged Elm (Ulmus alata), which features corky ridges on the twigs.
Foraging Tips
Look for mature trees near rivers and streams or in older municipal parks. Look for the distinct vase shape of the crown and examine fallen or lower leaves for the classic asymmetrical base and sharp double teeth.
Toxicity Warning
Non-toxic. The plant parts are safe for humans and animals.