American Sweetgum

Basic Information
Tree ID: 
11
Family: 
Altingiaceae
Genus and species: 
Liquidambar styraciflua
Description: 
The American sweetgum is a large shade tree with an ovular shape. It can be found throughout most of the United States as a forest tree in the Southeast and an ornamental in gardens and cities. This tree is often planted in parks where its height, ranging from 70-120 feet, and sprawling branches, spreading 40-50 feet, create shade for visitors. You can identify the American sweetgum by its star-shaped leaves and hard, spiky, spherical fruits. This specific American sweetgum grows along Prospect Street, just above the Marsh Botanical Gardens and across from the Farnam Memorial Gardens.
Location
Area: 
Marsh and Farnam Gardens
Collected Data
Tree shape: 
Oval
Date of tree entry: 
04/21/2014
Height: 
29.92 m
Diameter at breast height: 
1.00 m

Bark
The American sweetgum gets its scientific and common name from the gummy sap that is found directly under that bark and seeps out when the tree is wounded. This resin is sometimes called "liquid amber" because of its golden color and sweet odor. The bark on the trunk is light gray in color with deep, rounded ridges. In some trees (especially in the northern part of the range) the bark on the twigs and branches is one of the tree's more distinctive features: it attaches by edges instead of by broad surfaces so that the twigs appear to be winged!
Twigs & branches
This tree branches in a conical form and forms a uniform (smooth) canopy. The new twigs every year are reddish brown in color and sometimes covered in corky "wings."
Foilage
The leaves of the American sweetgum look like glossy five-pointed stars (though some leaves can have up to seven points). They are arranged alternately along a branch and the margins of each point have tiny serrations with glands full of tannins (perhaps as an anti-herbivory defense). In autumn, the green leaves turn yellow, red, orange or purple depending on the cultivar.
Reproductive Structures
Appearing between March and May as the new leaves emerge, these green flowers are monoecious (that is, flowers are unisexual and both the male and female flowers occur on the same tree). The staminate flowers (male) form clumps called racemes (they look something like green pyramids made of balls of green stamens) and the pistillate flowers (female) occur clumped in a spherical inflorescence, or cluster of flowers.
Fruit
Each of these balls contains a cluster of about sixty capsule fruits and within each fruit there are 1-2 seeds. The woody, spiky clusters are about 1-1.5 inches across and many hang on the tree throughout the winter. While they can be confused with sycamore fruits (see the tree page on the American sycamore) because of their shape and their persistance through winter, sweetgum fruit balls are hard and keep their shape after the seeds have been dispersed while the softer fruits of the sycamore disintegrate as the seeds are dispersed.
Seasons
  • Fall
  • Winter
  • Spring
  • Summer
Research
Natural range of distribution: 
Habitat: 
Although it can be found in many regions of the United States, the American sweetgum is most prevelent in the southeast states. The cloud forests of Mexico and Central America are also home to the tree. The map above shows the natural range of the tree though it can be planted much farther north.
Origin, history, and uses: 

The first-known written mention of the American sweetgum dates back to 1519, when the resinous liquid amber was used in ceremonies between Spanish conquistador Cortez and Aztec emperor Montezuma. In the past, this tree has been used for the making of soaps, adhesives, and in medicines, particularly by Native Americans. In modern times, the hardwood has become second only to oak for the carpentry of fine furniture and has become a common type of firewood in the United States. Due to its vibrant colors during the Fall season, the tree is often planted ornamentally both in public parks and private plots. The name sweetgum comes from the Native Americans who would peel back the bark, scrape off the resin, and chew the resin as one would chew gum.

Phenology: 
From late March to early April, the flowers, fruits and leaves emerge. By mid-September, leaf buds form and remain dormant throughout the winter.
References: 

http://lorax.opp.psu.edu/descriptions/tree.asp?cname=Sweetgum,+American

http://commons.wikimedia.org/wiki/File:Liquidambar_styraciflua_peculiar_…

http://en.wikipedia.org/wiki/Liquidambar_styraciflua

http://bobklips.com/treeflowers6.html

http://www.tpwd.state.tx.us/huntwild/wild/species/sweetgum/

http://www.rngr.net/publications/tree-improvement-proceedings/neftic/196…

Range map: ”Liquidambar styraciflua range map 4” by Elbert L. Little, Jr., of the U.S. Department of Agriculture, Forest Service - USGS Geosciences and Environmental Change Science Center: Digital Representations of Tree Species Range Maps from: Elbert L. Little, Jr. (1971), Atlas of United States trees, Vol. 1, conifers and important hardwoods: U.S. Department of Agriculture Miscellaneous Publication 1146, 9 p., 200 maps.. Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Liquidambar_styraciflua_range_map…

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