Tree of the Month: American Sweetgum

​The American Sweetgum tree is scientifically known as Liquidambar styraciflua, and known colloquially in different areas as the American storax, hazel pine, bilsted, redgum, satin-walnut, star-leaved gum, alligatorwood, or even just sweetgum. 

The sweetgum name actually comes from the sap of the tree, which is used to make—you guessed it—chewing gum. The sap has been called everything from liquid amber (which is, incidentally, where the genus Liquidambar comes from) to copalm basalm, and is also used medicinally and even as resin for stringed instruments.

If you’re like us, though, then you just know this tree as “the tree that makes those spiny gumballs I used to play with as a kid and only ever seemed to step on when I was barefoot and therefore vulnerable.”

Those spiny gumballs are actually the fruit of this deciduous tree. Each one conceals seeds behind that barbed exterior—when they first drop, they’re actually pretty soft, and only get hard and pokey once they’ve released their seeds. Everybody from goldfinches and sparrows to chipmunks and squirrels enjoy eating these seeds, which makes them an ideal addition to parks and wildlife refuges, but may cause a nuisance in your yard. While they’re most commonly called gumballs, the fruit is also referred to as burrs, spike balls, sticker balls, and (our personal favorite) space bugs. 

​The reason you find them almost everywhere is because the sweetgum is a monoecious species, which means each tree has both male and female reproductive organs—in this case, pistillate and staminate flowers (each flower will contain one or the other, but never both).

​These flowers bloom from around March to May, depending on the area, but can persist all the way through the fall and winter where temperature permits. Appearance-wise, they don’t really look like what you think of when you hear the word “flower;” they look more like little pyramids, sometimes with some red-orange color, but mostly just a lighter green than the surrounding leaves. The untrained eye would easily mistake them for more foliage rather than flowers.

​​American sweetgums are actually characterized by their leaves, which have a unique star shape. Mostly, we’re talking 5-point stars, but occasionally you’ll find a 3- or 7-point star hiding in the foliage—some people even consider this a sign of good luck, like finding a four-leaf-clover! Up close, each leaf has small “teeth” along the margins of their 4- to 7-inch length. During the spring and summer, the leaves are a dark, rich green with a light gloss; in fall, they turn gorgeous arrays of yellows, oranges, purples, and reds, and linger on their branches much longer than other tree species.

 ​​The last defining feature of the sweetgum is the bark. Usually, the bark is light brown in color, with random reddish, greyish, and brownish streaks and scaly ridges. Around their maturity age of 20 to 25 years, the bark will begin to accrue lots of deep fissures; these cracks, when coupled with the vertical way the bark attaches to the tree (rather than horizontally, like other trees), give the bark a rather “reptilian” appearance. This is actually where the name “alligatorwood” comes from—if you squint, any branch could look like the back of a gator.

​The sweetgum is one of the fastest-growing trees around, clocking anywhere from 13 to 24+ inches a year. Once established, the tree takes on a pyramidal or egg-like shape, and will continue to grow at rapid rates. On average and without human interference, sweetgums will live for hundreds of years, reach heights of 60 to 75 feet, trunks 2 to 5 feet in diameter, and crown spreads of 40 to 50 feet!

To reach its full potential, the American sweetgum needs about 6 hours of direct, unfiltered sunlight per day, which isn’t usually a problem here in the South. They have a moderate drought tolerance, and they aren’t too picky about soil composition, so they do A-okay in Georgia red clay. Just be sure to leave plenty of space to account for the roots—the sweetgum will end up with an extensive root system that you don’t want destroying your driveway or crowding out your flower garden.

Did You Know?

​The American sweetgum is especially resistant to attack by insects, which makes them common trees to plant in reforestation projects and reclamations of former mineral mines. They can also fix nitrogen and promote soil health, making them popular choices for ecosystem restoration.

​If you can tolerate the prickly gumballs all over your yard, the American Sweetgum is a gorgeous addition to any landscape., especially for nature enthusiasts who want to attract small mammals and birds to come over for a visit.

Author

Emily Casuccio is sister and sister-in-law to Rebekah and Scott Rushing, and has over half a decade of experience in copywriting, copyediting, proofreading, and developmental storyboarding. She's worked with both published and undiscovered authors on both fiction and nonfiction, and takes pride in supporting local businesses. Her passion lies in the written word and helping authors of all capacities realize their dreams and achieve their fullest potential. To learn more about her, read samples of her work, or contact her, visit her online portfolio.

Sources:
Yale University: American Sweetgum
Arbor Day Foundation: American Sweetgum
​Liquidambar styraciflua