It’s the Tree of the Month for January 2025!

American Sycamore, American Planetree, Buttonwood

Platanus occidentalis

American Sycamore (Platanus occidentalis, hereafter, simply Sycamore) is one of our most beautiful and recognizable trees. In girth, it’s North America’s largest deciduous tree, and according to some sources, has the largest simple leaf. Its mottled white, tan, and brown bark is especially striking in winter, when all of the leaves are down. (Notice that “Sycamore” in American usage is the same as “Plane” in England and elsewhere. In British usage, “Sycamore” is a species of Maple). 

Leaves

Sycamore has large, alternately-arranged leaves with palmate veins. Alternately-arranged leaves are not attached directly across from one another. Palmately-veined leaves have multiple primary veins attached at the stem, whereas pinnately-veined leaves have a single primary vein with secondary veins attached to it along its length. 

Sycamore leaves can be large, ranging from 4 to 8 inches wide, with 3 to 5 lobes. The stems are round and generally longer than 1 inch, but shorter than the similar-looking Sugar Maple stem. Notice also that Sycamore sinuses – the low areas between lobes – are much shallower than those of Sugar Maple. Sycamore leaves turn yellow or brown in the fall, but they do not turn orange or red like some maples. 

Stipules

Identify Sycamores more easily through its stipules, especially in juveniles, before they develop their distinctive bark. Stipules don’t occur on all trees, and they can take various forms, such as spines, tendrils that help climbing plants grasp, or leaf-like appendages that increase the tree’s photosynthesis. Its stipules are leaf-like, but they lack stems and look like they’ve been impaled on the twig. Not all Sycamores have these stipules, but in my experience, they’re most common in young saplings, and most visible in winter, since they often persist long after the leaves have fallen. 

Fruits

Sycamore fruits are also very distinctive, and consist of 1-inch diameter spheres, hanging from a slender stalk, that break up into numerous nutlets with soft, hairy tufts. Sweetgum trees (Liquidambar styraciflua) have similar fruits, but they’re hard, and they have numerous sharp spikes. Few Ohio trees have fruits this size, so Sycamores in winter are very recognizable, especially if you can see whether or not the fruits have spikes. 

Bark

Mature Sycamore trees are easily recognized by, and loved for, their peeling, mottled white, tan, and brown bark. It might help to remember that the bark looks like camouflage, or “camo” paint, and camo is in the name, syCAMOre. Bark can exfoliate for various reasons, but among others, it can help the tree rid itself of algal buildup and accumulation of smoke or pollution. 

Although not as easily described as leaf shape, bark is visible every day of the year, and is clearly visible on tall trees with leaves high in the canopy. Recognition of bark was very important in earlier times. Farmers would fell trees in winter, when there were no crops to tend, or mosquitoes, bugs, or snakes to deal with. In winter, much of the tree’s sap would be in the roots, so the lumber would already be partly dried.

In the days of miserable, rutted mud roads, it was easiest to haul heavy loads over snow in a sleigh. But a word of caution when identifying trees by their bark – look at the whole tree. The mature bark on the lower part of a tree can look very different than the juvenile bark on the upper part. Sycamore’s signature camo bark is present on mature trees, but juvenile trees, and the upper parts of mature trees, have smooth white bark, and the bases of old trees have brown, scaly bark. 

Sycamores in Ohio

There are two common Sycamores in Ohio. Normally found in woods and creeksides, the native species is, of course, the American Sycamore. The London Planetree (Platanus x acerifolia) is a hybrid of the Oriental Planetree (P. orientalis) and the American Sycamore, and is more common in landscaping, because of its greater tolerance of urban conditions. London Planetree can be distinguished by its greenish bark, and the fact that two or more of its fruits often hang from a single stem, whereas American Sycamore fruits are single. 

Mature Sycamores typically have a height of 60 to 80 feet and a trunk diameter of approximately 3 feet. Ohio’s Champion Sycamore, located in Ashland County, has a height of 100 feet, a trunk diameter of 11.6 feet, and a crown width of 101 feet. (However, this tree, located in Jerome, Ohio, is in decline, and Highbanks Metro Park in Franklin County claims to have Ohio’s newest Champion). 

Monumental Trees of the United States does not indicate an overall champion, but they list the tallest Sycamore as 149 feet, and the largest in girth as 32 feet! Both are in Pennsylvania. Sycamore trunks can reach impressive diameters, and because they often hollow out, there are many historical accounts of people living in them on hunting trips or while building a permanent dwelling. Rebecca Rupp’s Red Oaks and Black Birches tells of a Sycamore in Ohio that could reportedly hold 15 men on horseback, or 40 without horses. Sycamore grows relatively quickly and can live for over 250 years. 

Similar Trees

Because of its distinctive bark, the only tree that Sycamore is likely to be confused with is London Planetree, which has greener bark and fruits that often hang in groups of 2 or more per stem. Sycamores are most common in natural areas, while London Planetrees are more common in landscaping. The City of Columbus Street Tree Inventory indicates that London Planetree is the City’s 8th most common tree, while American Sycamore is the 76th. 

ID Summary

White, tan, and brown camo bark on mature trees, leaf-like stipules common on juvenile trees. Soft, spherical 1-inch fruits, hanging one per stem. Maple-like leaves with shallow sinuses. 

Sycamores are most abundant in wet areas, especially river banks, due to their need for sunlight and water. However, they are also found in upland areas, because Ohio’s clay-rich glaciated soils tend to hold water. P. occidentalis does not fare well in areas subject to fire, due to its thin bark. Lucy Braun’s The Woody Plants of Ohio indicates that Sycamore is found in every one of Ohio’s 88 counties. Sycamore occurs in all of the eastern states, as far north as Maine, and as far south as Mexico. 

Wood uses

Sycamore lumber has a Janka hardness of 770 lbf and a density of 0.55 g/cc, according to the Wood Database, compared to the median of my list of 73 Ohio trees of 1,075 lbf and 0.64 g/cc. It’s wood is light colored, and as is often the case for pale woods, lacking in durability (rot resistance). The grain of the Sycamore is relatively fine, and it takes paint and stains well. Sycamore is fairly easy to work with, but it occasionally causes problems during planing or cutting due to its cross grain.

Wood from Sycamore is used for flooring, furniture, veneer, butcher blocks, pallets, paper pulp, and other indoor applications, but its low rot resistance makes it unsuitable for outdoor use. Sycamore’s tendency to decay often causes the trees to hollow out, limiting the availability of large boards. Quarter-sawn boards, i.e. those sliced through the center of the log, have a lovely lace pattern, and are often used for decorative objects. Sycamore’s cross grain makes it difficult or impossible to split, which, with its relatively low heat value, makes it poor firewood. 

Medicinal uses

Natives of the Eastern U.S. made extensive use of Sycamore for medicinal purposes. The Native American Ethnobotany Database lists the following conditions that were treated with infusions of Sycamore bark or roots: 

Cherokee: 

• Menstrual pain,
• Dysentery,
• Coughs,
• Emetic to induce vomiting,
• Urinary problems.

Creek: 

• Tuberculosis.

Delaware: 

• Throat problems.

Iroquois:

• Rheumatism,
• Skin conditions.

Meskwaki:

• Internal pain,
• Blood purifier,
• Cleaning cuts,
• Lung and throat problems. Additionally, the Meskwaki ate Sycamore bark to get fat!

Other uses

We take for granted that we can cut boards in any direction in a matter of seconds. But the early Settlers made all of their cuts by hand, so if they wanted long boards, they split the wood parallel to grain with an ax or a froe, whenever possible. But because Sycamore resists splitting, they would typically choose other woods for making wood lath, siding, and the likes. Sycamore’s resistance to splitting made it ideal for buttons – perhaps the source of its nickname – and for simple wheels. A slice of Sycamore log made an adequate wheel. Sycamore split resistance also made it good for bowls. 

P. occidentalis leaves are eaten by a number of insects, including the Sycamore Tussock Moth (Halysidota harrisii) and the Sycamore Lace Bug (Corythucha ciliata). White-Tailed Deer occasionally also browse on the leaves and twigs. The seeds are consumed by Goldfinches, Purple Finches, and Dark-Eyed Juncos. Sycamore’s tendency to hollow out make them an important habitat for various owls, rodents, bats, and even bears. 

It was once common to make proclamations, treaties, and agreements beneath large trees. In 1792, at 68 Wall Street, the terms for the New York Stock Exchange were signed beneath a Sycamore, and the agreement came to be known as the “Buttonwood Agreement”.  

In literature

According to Red Oaks and Black Birches, the early Colonials recognized a connection between wet areas and Sycamores. But instead of mosquitoes, which also thrive in wet areas, people blamed the trees. 

The historian Herodotus described the love that the Persian King Xerxes had for a Sycamore. Xerxes had the tree hung with golden ornaments and he even assigned it a bodyguard. Xerxes’ court encouraged him to leave his beloved tree, and he eased his sorrow forever after by wearing a medallion with an engraving of the Sycamore. 

It gets stranger. According to Diana Wells’ Lives of the Trees, Sycamore got its name from a variety of fig tree, Ficus sycomorus – believed to be Adam and Eve’s only apparel. When medieval plays depicted the first couple, they clothed them with the largest available leaves, which came from the Plane tree. The association between Plane trees and F. sycomorus stuck, and the Plane tree came to be called ”Sycamore”. The origin stories of names are notoriously unreliable, but if this one’s not true, I don’t want to know.

Call them what you will – Sycamore, Plane, or Platanus, their mottled bark low on the tree, changing to bright white in the upper branches, make a beautiful sight, especially in winter.