What Is a Sweet Gum Tree?

Few trees produce as interesting a fruit as the sweet gum (Liquidambar styraciflua). This member of the witchhazel family grows in the United States and Mexico not only in the wild, but also as a cultivated landscaping species. The fruits, described by the University of Connecticut Plant Database as resembling a mace, work against it as a street tree but give sweet gum winter interest and use on your lawn as a shade or specimen species.

Geography

Sweet gum grows in U.S. Department of Agriculture plant hardiness zones 5 through 9. In a natural scenario, the tree thrives in damp ground on slopes and valleys, or in mixed forests and along streams. Sweet gum is native from the southwestern counties of Connecticut south to the middle of Florida and west to Texas. The tree has an extended range into the mountainous regions of Guatemala and Mexico.

Size and Form

Heights of the sweet gum range between 60 and 80 feet in most cases, but some grow to 100 feet tall. Widths of between 40 to 60 feet are not uncommon for this tree. The trunk measures between 18 inches and 3 feet wide. Mature sweet gums feature a long, straight trunk. The immature specimen has a pyramidal form. Older sweet gums develop a rounded, oval crown.

Foliage and Fruit

The leaves on a sweet gum are similar to those of a maple, with a star shape formed by the five-to-seven lobes. Measuring between 4 and 8 inches in length and width, these green leaves are a major asset come autumn, turning shades of burgundy, red, yellow and orange. The greenish-yellow flowers of May, though not conspicuous, result in spiny balls. These fruits have a prickly exterior, are hard and spherical and change from green to brown. Falling off the tree in winter and spring, they create a mess and are a potential danger to anyone stepping on them.

Varieties

"Grazam" is a cultivar of the sweet gum known for shiny green foliage that becomes red-purple to orange in autumn. The "Gumball" and "Oconee" cultivars grow to 15 feet high. "Moraine" is a bit more tolerant of cold climates, with the ability to grow faster than the parent species. "Silver King," "Golden Treasure" and "Variegata" are types of sweet gum with variegated leaves. "Rotundifolia" does not produce fruit, and its foliage possesses rounded lobes rather than pointy ones.

References

• University of Connecticut Plant Database: Liquidambar Styraciflua
• Missouri Botanical Garden: Liquidambar Styraciflua
• "National Audubon Society Field Guide to Trees: Eastern Region"; Elbert L. Little; Revised 2008