Liquidambar styraciflua
Liquidambar styraciflua, commonly known as the American sweetgum among other names, is a deciduous tree in the genus Liquidambar native to warm temperate areas of eastern North America and tropical montane regions of Mexico and Central America. Sweetgum is one of the main valuable forest trees in the southeastern United States, and is a popular ornamental tree in temperate climates. It is recognizable by the combination of its five-pointed star-shaped leaves and its hard, spiked fruits. It is currently classified in the plant family Altingiaceae, but was formerly considered a member of the Hamamelidaceae.
Names
This plant's genus name Liquidambar was first given by Linnaeus in 1753 from the Latin liquidus and the Arabic , in allusion to the fragrant terebinthine juice or gum which exudes from the tree. Its specific epithet styraciflua is an old generic name meaning 'flowing with storax'. The name "storax" has long been confusingly applied to the aromatic gum or resin of this species, that of L. orientalis of Turkey, and to the resin better known as benzoin from various tropical trees in the genus Styrax.The sweetgum has a Nahuatl name, Ocotzocuahuitl, which translates to 'tree that gives pine resin' from ocotl, tzotl, cuahuitl, which refers to the use of the tree's resin.
The common name "sweetgum" refers to the species' "sweetish gum", contrasting with the blackgum, only distantly related, with which the sweetgum overlaps broadly in range. The species is also known as the "redgum", for its reddish bark.
History
The earliest known published record of L. styraciflua is in a work by Spanish naturalist Francisco Hernández published posthumously in 1615, in which he describes the species as a large tree producing a fragrant gum resembling liquid amber, whence the genus name Liquidambar. In John Ray's Historia Plantarum it is called Styrax liquida. However, the first mention of any use of the amber is described by Juan de Grijalva, the nephew of the governor of Cuba, in the year 1517.Juan de Grijalva tells of gift exchanges with the Mayas "who presented them with, among other things, hollow reeds of about a span long filled with dried herbs and sweet-smelling liquid amber which, when lighted in the way shown by the natives, diffused an agreeable odour."
The species was introduced into Europe in 1681 by John Banister, the missionary collector sent out by Bishop Compton, who planted it in the palace gardens at Fulham in London, England.
Fossil record
An ancestor of Liquidambar styraciflua is known from Tertiary-aged fossils in Alaska, Greenland, and the mid-continental plateau of North America, much farther north than Liquidambar now grows. A similar plant is also found in Miocene deposits of the Tertiary of Europe.Description
Size
L. styraciflua is a medium-sized to large tree, growing anywhere from in cultivation and up to in the wild, with a trunk up in diameter on average. Trees may live to 400 years. The tree is a symmetrical shape and crowns into an egg shape when the branches get too heavy after its first two years of cultivation.Bark and branches
The bark attaches itself to these in plates edgewise instead of laterally, and a piece of the leafless branch with the aid of a little imagination readily takes on a reptilian form; indeed, the tree is sometimes called "alligatorwood".The bark is a light brown tinged with red and sometimes gray with dark streaks and has a density of. It is deeply fissured with scaly ridges. The branches carry layers of cork. The branchlets are pithy, many-angled, winged, and at first covered with rusty hairs, finally becoming red brown, gray or dark brown. As an ornamental tree, the species has a drawback—the branches may have ridges or "wings" that cause more surface area, increasing weight of snow and ice accumulation on the tree. However, the wood is heavy and hard with an interlocking grain, but is difficult to season.
Leaves
The leaves usually have five sharply pointed palmate lobes. They are wide on average and have three distinct bundle scars.They are long and broad, with a petiole. The rich dark green, smooth, shiny, star-shaped leaves generally turn brilliant yellow, orange, red, and purple colors in the autumn. Its reds and yellows compare to those of the maples, and in addition it has the dark purples and smoky browns of the ash. However, in the northern part of its range, and where planted in colder areas, the leaves are often killed by frost while still green. On the other hand, in the extreme southern or tropical parts of its range, some trees are evergreen or semi-evergreen, with negligible fall color. The base is truncate or slightly heart-shaped. They contain tannin and when bruised give a resinous fragrance.
While the starry five-pointed leaves of Liquidambar resemble those of some maples, Liquidambar is easily distinguished from Acer by its glossy, leathery leaves that grow in an alternate pattern, and not in pairs on the stems. Luna and promethea moth caterpillars feed on the leaves.
Flowers
The flowers typically appear in spring and persist into autumn, with some persisting into winter. They are typically about in diameter and are covered with hairs. The flowers are unisexual and greenish in color. Staminate flowers in terminal racemes long, the pistillate in a solitary head on a slender peduncle borne in the axil of an upper leaf. Staminate flowers destitute of calyx and corolla, but are surrounded by hairy bracts. Stamens indefinite; filaments short; anthers introrse. Pistillate flowers with a two-celled, two-beaked ovary, the carpels produced into a long, recurved, persistent style. The ovaries all more or less cohere and harden in fruit. There are many ovules but few mature.Fruit
The distinctive compound fruit is hard, dry, and globose, in diameter, composed of numerous capsules. Each capsule, containing one to two small seeds, has a pair of terminal spikes. When the fruit opens and the seeds are released, each capsule is associated with a small hole in the compound fruit.Fallen, opened fruits are often abundant beneath the trees; these have been popularly nicknamed "burr balls", "gum balls", "space bugs", "sticker balls", "spike balls", or "monkey balls".
The fruit is a multicapsular spherical head and hangs on the branches during the winter. The woody capsules are mostly filled with abortive seeds resembling sawdust. The seeds are about thick, winged, and wind-dispersed. Goldfinches, purple finches, squirrels, and chipmunks eat the seeds of the tree. The seeds stratify within 30–90 days at or soaked in water for 15–20 days.
The long-stemmed fruit balls of Liquidambar resemble those of the American sycamore or buttonwood, but are spiny and remain intact after their seeds are dispersed; the softer fruits of Platanus disintegrate upon seed dispersal. The long-persisting fallen spiked fruits can be unpleasant to walk on; sweet gum is banned in some places for this reason. In abundance, they can leave a lawn lumpy. The winter buds are yellow brown, long, acute. The inner scales enlarge with the growing shoot, becoming long, green tipped with red.
Distribution
Sweetgum is one of the most common hardwoods in the southeastern and Mid-Atlantic United States, where it occurs naturally in lowlands from southwestern Connecticut south to central Florida, through central Ohio and west to Illinois, southern Missouri, and eastern Texas, but not colder highland areas of Appalachia or the Midwestern states. The species also occurs in Mexico from southern Nuevo León south to Chiapas, as well as in Guatemala, El Salvador, Belize, Nicaragua and Honduras. In Mexico and Central America, it is a characteristic plant of cloud forests, growing at middle elevations in various mountainous areas where the climate is humid and more temperate.The US government distribution maps for this species are incorrect concerning the southern limit of distribution in Florida. This species occurs abundantly at Highlands Hammock State Park in Sebring, Highlands County, Florida, and even southwest of Lake Okeechobee.
Uses
Wood
Sweetgum is one of the most important commercial hardwoods in the Southeastern United States. Its wood is bright reddish brown and may have black grain in the heartwood; it is heavy, straight, satiny, and close-grained, but not strong. It takes a beautiful polish, but warps badly in drying. The wood has a specific gravity of 0.5910. It is too liable to decay for outdoor use.In the carpentry industry, the timber is referred to as satin walnut and is one of the most important materials for plywood manufacturers. It is used for furniture, interior trim, railroad ties, cigar boxes, crates, flooring, barrels, woodenware, and wood pulp. It is also used for veneer for plywood. The wood is very compact and fine-grained, the heartwood being reddish, and, when cut into planks, marked transversely with blackish belts. Sweetgum is used principally for lumber, veneer, plywood, slack cooperage, fuel, and pulpwood. The lumber is made into boxes and crates, furniture, cabinets for radios, televisions, and phonographs, interior trim, and millwork. The veneer and plywood, are used for boxes, pallets, crates, baskets, and interior woodwork. It was formerly used in the interior finish of railroad sleeping cars. Being readily dyed black, it is sometimes substituted for ebony for such uses as inexpensive picture frames. The wood is also used to make chopsticks for the East Asian market, as it has a naturally light color with appeal to certain segments of the Asian market.