Environment Planet Earth Identifying the Sweetgum Tree By Steve Nix Steve Nix Writer University of Georgia Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. Learn about our editorial process Updated July 8, 2022 Share Twitter Pinterest Email DigiPub / Getty Images Planet Earth Outdoors Weather Conservation American sweetgum trees, or Liquidambar styraciflua, are sometimes called redgum largely because of the distinct color of this older heartwood and its star-shaped leaves in the fall. Also called star-leaved gum, gumtree, and alligator-wood, this moderately-sized deciduous tree is common in the eastern United States, and can be found in small numbers in Mexico and as far south as Nicaragua. Sweetgum trees make for good shading foliage because they keep their leaves deep into fall. A study of the Chinese sweetgum, Liquidambar formosana, suggests they are also efficient contributors to carbon sink because they retain high photosynthetic activity even as their leaves begin to drop. This iconic tree is easy to identify, in large part because of its distinctive leaves and notable fruit. Where to Find Sweetgum Trees Sweetgum trees are found in parts of Asia and in the Americas. You'll find this hardwood in a variety of environments, but it thrives in the moist soils of lower lands and poorly-drained areas, and can also be found in mixed woodlands. Considered a pioneer species, the sweetgum tree can grow beyond 100 feet and is often found in the aftermath of a clearcut. Though most abundant east of the Mississippi River and especially in the southern U.S., the sweetgum tree is one of the most common tree species in the eastern United States and has spread in small groups south to Central American countries including Belize, Guatemala, El Salvador, and Honduras. Leaves and Fruit of the Sweetgum Shane Vaughn / Wikimedia Commons / CC BY 3.0 The straight trunk of a sweet gum tree is characterized by gray-brown bark that has narrow, deep ridges. The star-like leaf has five or seven lobes or points and turns from green in summer to yellow or purple in autumn. This leaf is borne on corky-winged limbs, and the fruit is a conspicuous spiked ball that grows in clusters. Look for the star-shaped leaf as foliage grows in the spring, and note the dried seed balls under the tree. Roundleaf sweetgum, or Liquidambar styraciflua rotundiloba, has star-shaped leaves with three to five lobes that have rounded tips. This variant, also known as fruitless sweetgum or thornless sweetgum, produces fewer if any sweetgum balls, making it better for urban areas, though like the fruit-bearing sweetgum, it has extensive root systems that can disrupt concrete. Sweetgum Sap The Liquidambar genus gets its nickname from the sap the trees produce; the brown resin can be hardened to make gum. But the sap, which is called storax, is more than just a chewy candy: Sweetgum trees and their sap have been used for medicinal purposes for hundreds of years, and researchers continue to study the use of sweetgum trees in medical settings, including the use of the storax to fight multidrug-resistant bacteria. Sweetgum bark, leaves, and seeds contain shikimic acid, which has been studied for its antiviral properties. Sweetgum seeds have been studied for anticonvulsant effects, and storax has been included in research to prevent hypertension and cancer. Oils from sweetgum trees have shown potential as a natural pesticide against the pine wood nematode Bursaphelenchus xylophilus, as well as an insecticide for Aedes aegypti, mosquitos known to transmit dengue fever. Frequently Asked Questions How many species of sweetgum tree are there? Four species are common in the sweetgum genus. In addition to the American sweegum, Asia is home to L. formosana, L. orientalis (Turkish sweetgum), and L. acalycina. What are sweetgum trees used for? Used as an ornamental shade tree, sweetgums offer a hardy option to homeowners, but do shed gumballs that can be a trip hazard. The wood of sweetgum trees is used in the production of plywood and veneer, while the sap, leaves, and bark have shown potential in medicinal applications. View Article Sources "Liquidambar Styraciflua L." Southern Research Station, U.S. Forest Service. Luo, Zidong, et al. “Photosynthetic Capacity of Senescent Leaves for a Subtropical Broadleaf Deciduous Tree Species Liquidambar Formosana Hance.” Scientific Reports, vol. 7, no. 1, July 2017, p. 6323. Lingbeck, Jody M., et al. “Sweetgum: An Ancient Source of Beneficial Compounds with Modern Benefits.” Pharmacognosy Reviews, vol. 9, no. 17, 2015, pp. 1–11. PubMed Central, "Know Your Trees." Mississippi State University Extension Service. "Liquidambar Styraciflua." Fire Effects Information System (FEIS) Index of Species Information. "Liquidambar Styraciflua 'Rotundiloba.'” North Carolina Extension Gardener Plant Toolbox. NC State Extension.