Liquidambar, commonly called sweetgum (sweet gum in the UK),gum,redgum,satin-walnut, or American storax, is the only genus in the flowering plant family Altingiaceae with 15 species. They were formerly often treated in Hamamelidaceae.
Both the scientific and common names refer to the sweet resinous sap (liquid amber) exuded by the trunk when cut.
They are all large, deciduous trees, 25–40 metres (82–131 ft) tall, with palmately 3- to 7-lobed leaves arranged spirally on the stems and length of 12.5 to 20 centimetres (4.9 to 7.9 in), having a pleasant aroma when crushed. Their leaves can be many colors such as bright red, Orange and yellow. Mature bark is grayish and vertically grooved. The flowers are small, produced in a dense globular inflorescence 1–2 centimetres (0.39–0.79 in) diameter, pendulous on a 3–7 centimetres (1.2–2.8 in) stem. The fruit is a woody multiple capsule 2–4 centimetres (0.79–1.57 in) in diameter (popularly called a "gumball"), containing numerous seeds and covered in numerous prickly, woody armatures, possibly to attach to fur of animals. The woody biomass is classified as hardwood.
In more northerly climates, sweetgum is among the last of trees to leaf out in the spring, and also among the last of trees to drop its leaves in the fall, turning multiple colors. Fall colors are most brilliant where autumn nights are chilly, but some cultivars color well in warm climates. Although a temperate species, at least one living Liquidambar tree survives in a hot and humid tropical city: Bangkok, Thailand.
Species within this genus are widespread in China, Korea, Thailand, Taiwan, Laos, Vietnam, Turkey, Rhodes, North America and Mexico up to Honduras). In cultivation they can be seen in warm temperate and subtropical climates around the world.
