Sycamore

Scientific Name: Platanus occidentalis. The genus name Platanus comes from the Greek word platanos, which has long been used to refer to different species of plane tree, Platanus orientalis. While orientalis means eastern, the species name for sycamore, occidentalis, is a Latin word meaning western.²

Common Name: Sycamore. Do the leaves remind you of any other trees? This tree was reportedly dubbed “sycamore” by European settlers because the leaves reminded them of a tree growing in Europe named sycamore (Acer pseudoplatanus), which adds a layer of confusion since that sycamore is really a maple!^1,2 Other common names include American sycamore and American plane tree—helpful clarification that this tree is not the one from Europe. Another name is buttonwood, referring to one of its uses as wood for making buttons!^1,3 Common names can be interesting, but also confusing. That’s why scientists prefer to use scientific names!

Family: Platanaceae (Planetree Family). This family consists of a single genus, Platanus, which in turn has a very small number of species—perhaps only 12! These tall trees are located in the northern hemisphere and have thin, scaly bark and broad, ovate leaves. Both the leaves and the bark are deciduous, meaning the outer layer of the bark as well as the leaves fall off the tree! Flowers grow in tight clusters resembling balls and are wind-pollinated. Globe-like seed heads consist of single winged seeds with long, tan hairs.^1,4

Average Height: 75-100 feet (can reach 150 feet tall!)

Description: Sycamore trees grow to be massive with large, spreading crowns. In more open areas, they are often as wide as they are tall, with trunks measuring 3–10’ across. The bark varies from reddish brown and scaly near the base to lighter gray higher up. The thin bark peels off, revealing the white inner bark and often creating a mottled camouflage pattern or, in the upper branches, areas that are entirely white. The branches zigzag and the buds are hidden—surrounded by the base of the leaf stalk. Leaves are deciduous, alternate, and palmately veined. Green leaves are 4–10” in both width and length, have 3–5 wide lobes, and coarse teeth. A leafy appendage encircles the twig near the base of the leaf stalk. Leaves and clusters of flowers appear together in spring. Each flowerhead consists of either yellow male or reddish female flowers, with both types present on the same tree. Flowers are wind-pollinated, and the globe-like seed heads are dense balls of winged seeds with fluffy tan hairs that often remain on the tree until late winter or spring. The distinctive peeling bark and spherical seed heads make this an easy tree to spot in the winter!^1,2,5,6

Bloom time: Apr – May

Notes: A hybrid tree, the London plane tree (Platanus x acerifolia) was created by crossing Platanus occidentalis with Platanus orientalis to produce a tree valued for use in landscaping. Known for tolerating pollution, this hybrid is used in many urban settings. How does it differ from our native sycamore? As compared to P. occidentalis, Platanus x acerifolia has narrower lobes, deeper sinuses, and more than one seed head per flowerstalk.⁶

Range: Found in every county within Virginia, it is common in the Piedmont and mountains, and frequent in the Coastal Plain. A tree of central and eastern North America, it ranges from Quebec and Maine south to Florida, and west to Texas and Nebraska, though it is absent from the upper midwest.^10,11

Geology/Soil: Prefers moist, well-drained soils but is tolerant of different soil composition (sand, gravel, clay, silt, loam) and pH.^1,6

Habitat: Found most frequently in moist areas such as floodplain forests, the banks of streams and rivers, seeps, swamps, fields, and sometimes in more disturbed areas in moist lowland to upland forests. Tolerant of pollution, it is often used in landscaping in parks and urban settings.^1,6,10

Flora associations: Found growing in floodplain forests and other moist habitats with a mix of plants that may include river birch (Betula nigra), black walnut (Juglans nigra), common hackberry (Celtis occidentalis), Eastern boxelder (Acer negundo var. negundo), silver maple (Acer saccharinum), pawpaw (Asimina triloba), spicebush (Lindera benzoin), false nettle (Boehmeria cylindrica), orange jewelweed (Impatiens capensis), poison ivy (Toxicodendron radicans), and often invasive species such as Japanese stiltgrass (Microstegium vimineum) and garlic mustard (Allaria petiolata). Do you see any of these species nearby?^6,11

Fauna associations: Remember, the flowers are wind-pollinated so there are no insect pollinators! The drab prominent moth (Misogada unicolor) specializes in eating sycamore and can be found in the late summer on the undersides of the leaves. Insect species may develop a strong association with particular tree species—which may sometimes be reflected in the common or scientific names. Leaf eaters of the sycamore include the sycamore tussock moth (Halysidota harrisii), a pygmy leafmining moth (Ectoedemia platanella), and the sycamore lace bug (Corythucha ciliata). The sycamore seed bug (Belonochilus numenius) eats the seeds, while the larvae of the sycamore heart borer (Chalcophorella campestris) bore into the wood. The sycamore treehopper (Telamona collina) and several leafhoppers in the genus Eratoneura feed by sucking on the sap of the sycamore.^6,7,8

Songbirds such as the American goldfinch (Spinus tristis), Carolina chickadee (Poecile carolinensis), and dark-eyed junco (Junco hyemalis) may be seen eating sycamore seeds, but these seeds are especially favored by purple finches (Haemorhous purpureus). Older trees provide homes for cavity nesting birds and mammals like barred owl, screech owl, chimney swift, tree squirrels, and bats.⁶

Human associations: Humans have found many medicinal and other uses for Platanus occidentalis. Indigenous Peoples use infusions of the bark to treat coughs, colds, sore throats, measles, and dysentery. Other medicinal uses range from treating rashes on infants to using it as an emetic. The Cherokee use the wood for building and buttons. Commercially, the wood is used for cabinets, furniture, and barrels.^2,9

We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!

1 “Platanus Occidentalis (American Plane Tree, American Sycamore, Buttonwood, Eastern Sycamore, Sycamore) | North Carolina Extension Gardener Plant Toolbox.” Plants.ces.ncsu.edu, plants.ces.ncsu.edu/plants/platanus-occidentalis/. Accessed 10 Dec. 2024.

2 “Platanus Occidentalis – Plant Finder.” Www.missouribotanicalgarden.org, www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a891. Accessed 10 Dec. 2024.

3 Boggs, Joe. “Ode to the Buttonwood Tree.” Osu.edu, 18 Oct. 2017, bygl.osu.edu/node/939. Accessed 10 Dec. 2024.

4 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, pp. 796-797.

5 “Virginia Tech Dendrology Fact Sheet.” Vt.edu, 2021, dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=36.

6 “American Sycamore (Platanus Occidentalis).” Illinoiswildflowers.info, 2019, www.illinoiswildflowers.info/trees/plants/am_sycamore.htm. Accessed 10 Dec. 2024.

7 “Search – Platanus occidentalis.” Bugguide.net, 2024, bugguide.net/index.php?q=search&keys=platanus+occidentalis. Accessed 10 Dec. 2024.

8 Wagner, David L. Caterpillars of Eastern North America : A Guide to Identification and Natural History. Princeton, N.J., Princeton University Press, 2005.

9 “BRIT – Native American Ethnobotany Database.” Brit.org, 2024, naeb.brit.org/uses/search/?string=platanus+occidentalis. Accessed 10 Dec. 2024.

10 “Digital Atlas of the Virginia Flora | Platanus Occidentalis L.” Vaplantatlas.org, 2024, www.vaplantatlas.org/index.php?do=plant&plant=663&search=Search. Accessed 10 Dec. 2024.

11 “Piedmont / Mountain Floodplain Forests and Swamps.” Virginia.gov, 2021, www.dcr.virginia.gov/natural-heritage/natural-communities/ncpa5. Accessed 10 Dec. 2024.

Definitions:

Palmately veined: Having veins that branch from a common point.

Sinus: A space between the lobes of a leaf.