How to Identify American Holly

Click here to learn more about the How to Identify article series.

A tall evergreen tree stands surrounded by larger deciduous trees that have lost their leaves in winter, with a blue sky overhead. For article on how to identify American holly.
Photo by Famartin, CCA-SA-4.0-INTL

Name: American Holly (Ilex opaca)

Range and typical habitat(s): Typically southeastern United States, from eastern Texas to the Atlantic coast, southern Missouri, and central Florida to scattered portions of New England. iNaturalist observations also place it in portions of Michigan, Illinois, Ohio, and Oklahoma, showing some expansion compared to the 2014 BONAP map, so its range may be expanding in response to climate change. In most of its range it is an understory tree growing in the shade of larger species. However, in Florida’s scrub habitat it grows as a shrub.

A photo of a tree limb with medium green leaves that are oval shaped with little spikes around the edges, and clusters of red berries, with sunlight creating light and dark patches in the picture. For article on how to identify American holly.
Photo by Derek Ramsay, GNU FDL 1.2

Distinguishing physical characteristics (size, colors, overall shapes, detail shapes): At first glance American holly looks quite similar to the European holly (Ilex aquifolium) so commonly used got holiday decorations (more about the differences between the two below.) It has medium to dark green oval-shaped leaves, sometimes with a yellowish tint, whose margins (edges) have concave curves between sharp points that are regularly spaced; large leaves may reach three inches long.

A close-up of a cluster of oval leaves with spiky edges and a green, waxy appearance. Hidden in the center are a few round, pale green berries. For article on how to identify American holly.The American holly’s leaves have a leathery, stiff texture, and may appear waxy, and the underside is paler, often yellow in color. Each leaf has a central vein (midrib) that is depressed, appearing almost like a deep crease. Thinner veins branch off of both sides of the midrib. Some leaves may display smooth margins instead of the more typically spiky ones, especially when they are high enough to be out of the reach of browsing herbivores like deer.

A photo of two very straight tree trunks right next to each other. They have pale gray bark with both vertical fissures, and finer horizontal lines, as well as various bumps and scars. The ground around them is covered in English ivy. For article on how to identify American holly.
Photo by Krzysztof Ziarnek, CCA-SA-4.0-INTL

The foliage stays green throughout the year rather than being shed in fall; a given leaf may stay on the tree for up to three years before being displaced by a new replacement leaf. The leaves grow in an alternate pattern along a twig, with each leaf growing a little further along the twig than the last. The tree’s branches and trunk are covered in pale gray bark that is relatively smooth, but may have horizontal and vertical striations, along with various nodes and bumps, and might also play host to white patches of microlichen colonies. Other lichens, as well as mosses, also may add color to the American holly’s bark.

An exceptional specimen of American holly can reach almost 100 feet tall when mature, though it grows slowly. Such large trees are generally a century or more old, and the oldest on record was just a few years shy of 150.

A cluster of small white flowers with four round white petals with slight pink tinges arranged around round, light green centers. The flowers are surrounded by dark green leaves. For article on how to identify American holly.The flowers of American holly are small (1/2″ or less across) with green centers and four (sometimes six) white petals that are broad with a rounded end, and whose tips curve back toward the plant. They grow in clusters of several flowers sprouting from one spot. American holly is dioecious, meaning that there are female and male plants; the males tend to reach sexual maturity a few years earlier than the females, but they all are generally reproducing by the age of ten.

A close-up of several small bright red berries on gray twigs, with spiky green leaves around them against a black background. For article on how to identify American holly.
Photo by Douglas Goldman, CCA-SA-4.0

When fertilized by insects the female flowers then turn into the well-known red berries. Technically these are drupes rather than true berries, with four seeds apiece, and while they start out green they ripen to a bright red. The berries are popular with birds like cedar waxwings (Bombycilla cedrorum), but are toxic to humans and our pets.

A bunch of leaves similar to those already seen, but darker green and much glossier in appearance. For article on how to identify American holly.
European holly (Ilex aquifolium)

Other organisms it could be confused with and how to tell the difference: Due to their similarity, American holly and European holly may easily be confused at first glance, and both prefer the understory of a forest. However, the European species does not grow as large. The leaves of European holly are darker and have a glossier appearance; the edges may also be more warped where those of American holly lie comparatively flat. Moreover, European holly grows more commonly along the west coast of North America, and is more sparse throughout American holly’s native range, especially outside of cultivated spaces.

A close-up of a cluster of white flowers similar to those previously seen with four petals around a significantly smaller green center. They are surrounded by oval shaped leaves with gently scalloped edges. For article on how to identify American holly.
Yaupon holly (Ilex vomitoria)

Yaupon holly (Ilex vomitoria) is another species native to the southeastern North America, particularly the Gulf Coast states and the southern third of the Atlantic coast. It is a much smaller shrub that rarely exceeds thirty feet tall, and its leaves are round with serrated or scalloped edges rather than the pointed margins of American holly. The petals of the flowers may not curve as much as on American holly.

A close-up of a dark green shiny leaf with mostly smooth edges but a few tiny teeth arranged along the edge. For article on how to identify American holly.
Dahoon holly (Ilex cassine). Photo by Douglas Goldman, CCA-SA-4.0

Dahoon holly (Ilex cassine) also grows in the extreme southeastern United States, from Louisiana to the southern tip of North Carolina, and primarily along the coastline except in Florida where it can be found across much of the peninsula. Its leaves are longer and more slender than those of American holly, and the margins are almost entirely smooth except for a series of very small spikes.

A cluster of green oval leaves with somewhat pointed tips, and serrated edged, photographed against a white background with some gray shadows on the left side. For article on how to identify American holly.
Possumhaw (Ilex decidua)

Possumhaw (Ilex decidua) has long, slender leaves with a gently pointed tip and serrated edges. This deciduous plant drops its leaves in fall, unlike the evergreen American holly.

There are other plants that have similar leaves to American holly but that grow out of its range, such as the various species of Oregon grape (Mahonia spp.) in the Pacific Northwest, and holm oak (Quercus ilex), for which the genus Ilex was originally named.

Further reading:

USDA: American Holly

North Carolina Extension Gardener Plant Toolbox: Ilex opaca

Missouri Botanical Garden Plant Finder: Ilex opaca

Native Plant Trust: Ilex opaca – American holly

University of Connecticut Plant Database: Ilex opaca

Did you enjoy this post? Consider taking one of my online foraging and natural history classes or hiring me for a guided nature tour, checking out my other articles, or picking up a paperback or ebook I’ve written! You can even buy me a coffee here!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.