Scientific Name
Liquidambar styraciflua
A common tree in the southeast quadrant of the U.S., sweet gum is admired for its glossy, five-pointed, star-shaped foliage and its often-striking fall color, which can range from yellow to crimson or combinations of those shades. It's found naturally as far north as New Jersey and southern Illinois and as far west as Texas, as well as on mountain slopes in Central America where it can avoid the tropical lowland heat it dislikes. Sweet gum has long been widely planted as an ornamental tree on the U.S. West Coast, where it's one of the few deciduous trees that provides fall color, but it's a relative newcomer in Colorado because until recently it was not considered hardy enough to withstand the winters here. However, with a somewhat warmer climate — especially in the more built-up urban areas of our region — and because the nursery industry has developed some cold-resistant strains, we now know that this tree can add to our canopy diversity.
Sweet gum trees in Denver are likely capable of reaching 50 feet in height, with varying silhouettes depending on the cultivar; some have been selected to remain relatively narrow. Their leaves have veins radiating from a central point and so can be confused with many maple species; however, they’re arranged alternately on the twigs, whereas maple leaves occur in opposing pairs. Often, the twigs sport longitudinal corky ridges reminiscent of bur oak twigs. The fruits of sweet gum trees are spiky balls (typically called "gum balls") that remain woody long after they fall from the trees, which makes them a nuisance especially for barefoot passersby. The other negative aspect of this tree is that it usually develops heavy surface roots that can damage sidewalks and paving, so they are best planted in open areas. The gum for which these trees were named is not often encountered unless it exudes from the trunks or larger branches when they're wounded; the resinous substance does have a sweet smell and has found medicinal applications. Sweet gum wood is also an important resource that is primarily used for utilitarian purposes, such as plywood, crates and similar products.