American Sweetgum – June 2013 Tree of the Month

by Ann Farnham, LLA

The American sweetgum, Liriodendron styraciflua, is a handsome, symmetrical and large tree which is native to the warm areas of eastern North America to the tropical mountainous areas of Mexico and Central America. The name, sweetgum, refers to the aromatic gum that seeps from wounds on the tree.

It can be recognized by its five-pointed star-shaped leaves and its hard, spikey fruits. A medium to fast grower, it usually grows to 60-80’ but it has been known to reach 120’ tall in the wild, with a straight trunk and a pyramidal shape when young, developing into an oval shape in maturity. The leaves measure 3-7 inches wide with a toothed edge, and may have five to seven pointed lobes.

The leaf color is a beautiful deep, glossy green in the summer which develops into a brilliant mixture of colors in the fall ranging from yellow, orange, and red to purple. The leaves are fragrant when bruised.

Flowering occurs from April to May, persisting into Autumn, with the male and female flowers on the same tree. The flowers are inconspicuous. What is not inconspicuous are the fruits, spherical gum balls the size of golf balls, hard and spikey, measuring 1 to 1.5 inches in diameter.

This is a popular ornamental tree which grows best in moist, acidic and well-drained soils. Sweetgum requires full sun and plenty of room for its root development. It is not very pollution or salt tolerant, and is susceptible to several insects and diseases.

Sweetgum wood is used in flooring, furniture, (it is often referred to as “Italian Mahogany,” or satin walnut), veneers; the pulp makes fine paper. The gum has been used to treat sciatica and “nerve weakness,” coughs, wounds and dysentery, and to make perfumes, cosmetics and chewing gum; the Aztecs mixed it with tobacco and smoked it in the court of the Mexican emperors. This tree is a favorite of the Yellow-bellied Sapsucker.

There are many cultivars (cultivated varieties) of sweetgum, including a short and shrubby variety called Gumball. Another cultivar is Rotundiloba, which is sterile and does not produce the prickly seed pods.

Care should be taken in siting a sweet gum. It is an excellent specimen in parks, lawns and as a street tree, but it needs a lot of space and a situation where stepping on the seed pods, litter, or a lumpy lawn will not be a factor.

A grove of sweet gums was donated to the Flight 93 Memorial in Shanksville, Pennsylvania.

The Ewing Environmental Commission (eec@ewingnj.org) welcomes suggestions for the Tree of the Month from all Ewing residents.