How to Identify an Elm Tree

Elm trees (genus Ulmus) share several distinctive features that, taken together, make them straightforward to identify with practice. This guide describes the key field marks and the most common confusions.

For species-level identification once a tree is confirmed as an elm, see Elm Species: A Complete Guide.

The four reliable elm field marks

1. Asymmetrical leaf base

Pull a leaf from the tree and look at where the leaf blade meets the petiole (stem). On every elm, one side of the leaf attaches noticeably lower than the other, giving the leaf base a distinctly lopsided look.

This asymmetric leaf base is characteristic of the genus and is the single most useful identification feature. A symmetrical leaf base rules out elm.

2. Doubly serrated leaf margins

Most elm leaves have double-toothed margins: each large tooth carries one or more smaller teeth on it, creating a sawtooth-on-sawtooth pattern. The regular alternation of large and small teeth is detectable by touch as well as by sight.

A few elms (Chinese elm, Siberian elm) have only single-toothed margins — but combined with the asymmetric base and other features, they're still recognizable.

3. Distinctive samaras (winged seeds)

Elm fruits are flat, papery, oval samaras with a single seed in the center or slightly off-center. Most elms produce them in spring — they look like small, pale-green-to-tan disc-shaped wafers, often abundant enough to carpet the ground beneath the tree.

The exception: Chinese elm (Ulmus parvifolia) flowers and fruits in late summer/early fall, which is itself a good identification feature for that species.

4. Branching pattern

Elms have a distinctive zigzag twig growth pattern — the small branchlets don't grow straight, but bend slightly at each leaf-bud node, creating a zig-zag silhouette visible against winter sky. The twigs are usually slender and somewhat flexible.

Some elms (especially American elm) have a strong overall growth pattern of a single trunk that splits into 3–6 large scaffold branches at 10–20 feet, each angling outward and upward — the classic vase shape. Not all elms show this clearly, but when present it's a strong sign.

Bark patterns by species

Bark is a useful secondary feature once the species has been narrowed:

Species | Mature bark
American elm | Light gray, deep furrows, broad flat-topped ridges; alternating brown/white inner bark layers when sliced
Slippery elm | Reddish-brown to gray-brown; mucilaginous reddish inner bark when sliced
English elm | Dark brown, deeply fissured into rectangular plates
Wych elm | Gray-brown, broad shallow fissures; smoother than American elm
Chinese elm | Mottled, exfoliating — patches of gray, green, orange, brown
Siberian elm | Gray-brown, deeply furrowed (NOT mottled — easy distinction from Chinese elm)

For more detail on each, see the individual species pages linked from Elm Species: A Complete Guide.

Common confusions with non-elm trees

A few tree species are mistaken for elms:

Hackberry (Celtis occidentalis): Has the same asymmetric leaf base as elm, but leaves are heart-shaped at the base, the bark is gray with distinctive corky warts, and it produces dark berries instead of samaras. Hackberry is in the same family (Cannabaceae now, formerly Ulmaceae) and shares some features.

Zelkova (Zelkova serrata): A close elm relative often planted as a DED-resistant elm substitute. Leaves are similar but the base is more symmetrical, the teeth are simpler, and the bark exfoliates in patches like Chinese elm but in a different pattern.

Birch (Betula spp.): Sometimes confused at a distance; birch has white or papery peeling bark and symmetrical leaf bases.

Identifying a sick or dying elm

When a confirmed elm shows signs of decline, see:

What Are the Symptoms of Dutch Elm Disease?

Dutch Elm Disease Symptom Checker

Differential Diagnosis Guide

For a confirmed-or-suspected DED case, contact information is in Who Should I Contact if I See Dutch Elm Disease?.

Identification with apps and tools

Mobile plant-ID apps (PictureThis, iNaturalist, Seek) handle most elm species accurately when given a clear leaf photograph showing the asymmetric base. They are less reliable for distinguishing Chinese elm from Siberian elm — for that distinction, manually check bark and flowering season.

Related pages

Elm Species: A Complete Guide

What are Dutch Elm trees?

American Elm (Ulmus americana)

Chinese Elm (Ulmus parvifolia)

Siberian Elm (Ulmus pumila)

References

Sherman-Broyles, S. L. (1997). "Ulmaceae". In Flora of North America, vol. 3. Oxford University Press.

Sibley, D. A. (2009). The Sibley Guide to Trees. Knopf.

Petrides, G. A. (1988). A Field Guide to Eastern Trees. Houghton Mifflin.