Liriodendron tulipifera
Liriodendron tulipifera—known as the tulip tree, American tulip tree, tulipwood, tuliptree, tulip poplar, whitewood, fiddletree, lynn-tree, hickory-poplar, and yellow-poplar—is the North American representative of the two-species genus Liriodendron. It is native to eastern North America from Southern Ontario and possibly southern Quebec west to Illinois, and east to southwestern Massachusetts, then south to central Florida and Louisiana.
The tulip tree is the tallest tree of the Nearctic temperate deciduous forest. It can grow to more than in virgin cove forests of the Appalachian Mountains, often with no limbs until it reaches in height, making it a very valuable timber tree.
This species is also fast-growing, without the common problems of weak wood strength and short lifespan often seen in fast-growing species. In 2024 the unusual combination of rapid growth with strong wood was explained. No longer called hardwood, tulip tree lumber is now called "midwood," a term created expressly for this wood.
The tulip tree is the state tree of Indiana, Kentucky, and Tennessee.
Description
The tulip tree is one of the largest of the native trees of eastern North America, known in an extraordinary case to reach the height of with the next-tallest known specimens in the range. These heights are comparable to the very tallest known eastern white pines, another species often described as the tallest in eastern North America.The trunk on large examples is typically in diameter, though it can grow much broader. Its ordinary height is and it tends to have a pyramidal crown. It prefers deep, rich, and rather moist soil; it is common throughout the Southern United States. Growth is fairly rapid.
The bark is brown, furrowed, aromatic and bitter. The branchlets are smooth, and lustrous, initially reddish, maturing to dark gray, and finally brown. The wood is light yellow to brown, and the sapwood creamy white; light, soft, brittle, close, straight-grained. Specific gravity: 0.4230; density:.
Winter buds are dark red, covered with a bloom, obtuse; scales becoming conspicuous stipules for the unfolding leaf, and persistent until the leaf is fully grown. Flower-bud enclosed in a two-valved, caducous bract.
The alternate leaves are simple, pinnately veined, measuring long and wide. They have four lobes, and are heart-shaped or truncate or slightly wedge-shaped at base, entire, and the apex cut across at a shallow angle, making the upper part of the leaf look square; midrib and primary veins prominent. They come out of the bud recurved by the bending down of the petiole near the middle bringing the apex of the folded leaf to the base of the bud, light green, when full grown are bright green, smooth and shining above, paler green beneath, with downy veins. In autumn they turn a clear, bright yellow. Petiole long, slender, angled.
April marks the start of the flowering period in the Southern United States ; trees at the northern limit of cultivation begin to flower in June. The flowers are pale green or yellow, with an orange band on the tepals; they yield large quantities of nectar.
- Flowers: May. Perfect, solitary, terminal, greenish yellow, borne on stout peduncles, long, cup-shaped, erect, conspicuous. The bud is enclosed in a sheath of two triangular bracts which fall as the blossom opens.
- Calyx: Sepals three, imbricate in bud, reflexed or spreading, somewhat veined, early deciduous.
- Corolla: Cup-shaped, petals six, long, in two rows, imbricate, hypogynous, greenish yellow, marked toward the base with yellow. Somewhat fleshy in texture.
- Stamens: Indefinite, imbricate in many ranks on the base of the receptacle; filaments thread-like, short; anthers extrorse, long, two-celled, adnate; cells opening longitudinally.
- Pistils: Indefinite, imbricate on the long slender receptacle. Ovary one-celled; style acuminate, flattened; stigma short, one-sided, recurved; ovules two.
- Fruit: Narrow light brown cone, formed from many overlapping samaras which are dispersed by wind, leaving the axis persistent all winter. September, October.
Taxonomy
Originally described by Carl Linnaeus, Liriodendron tulipifera is one of two species in the genus Liriodendron in the magnolia family. The name Liriodendron is Greek for "lily tree". It is also called the tuliptree Magnolia, or sometimes, by the lumber industry, as the tulip-poplar or yellow-poplar. However, it is not closely related to true lilies, tulips or poplars.The tulip tree has impressed itself upon popular attention in many ways, and consequently has many common names. The tree's traditional name in the Miami-Illinois language is oonseentia. Native Americans so habitually made their dugout canoes of its trunk that the early settlers west of the Appalachian Mountains called it Canoewood. The color of its wood gives it the name Whitewood. In areas near the Mississippi River it is called a poplar largely because of the fluttering habits of its leaves, in which it resembles trees of that genus. It is sometimes called "fiddle tree," because its peculiar leaves, with their arched bases and in-cut sides, suggest the violin shape.
The external resemblance of its flowers to tulips named it the Tulip-tree. In their internal structure, however, they are quite different. Instead of the triple arrangements of stamens and pistil parts, they have indefinite numbers arranged in spirals.
Distribution and habitat
In the Cretaceous age the genus was represented by several species, and was widely distributed over North America and Europe. Its remains are also found in Tertiary rocks.Today the tulip tree is one of the largest and most valuable hardwoods of eastern North America, thriving in temperate deciduous forests east of the Mississippi River. Its indeterminate pattern of continued growth in the latter month of the growing season can cause this species to be more susceptible to droughts and cease shoot growth after July in drier climates. It prefers mesic to moist, well-drained soils and is generally most common at low to mid-elevations, for example usually not found above 3000 ft elevation in Virginia.
It is native southern Ontario and northern Ohio south to the Gulf of Mexico and from extreme southern New York and Connecticut south to Louisiana and northern Florida. It extends south to north Florida, and has few natural populations west of the Mississippi River, but beyond its native areas it is found occasionally as ornamentals or escapes. Its finest development is in the Southern Appalachian mountains, where trees may exceed in height. It was introduced into Great Britain before 1688 in Bishop Compton's garden at Fulham Palace and is now a popular ornamental in streets, parks, and large gardens. The Appalachian Mountains and adjacent Piedmont running south from Pennsylvania to Georgia contained 75 percent of all yellow-poplar growing stock in 1974.
East Central Florida ecotype
Parts of east-central Florida near Orlando have an ecotype with similar-looking leaves to the coastal plain variant of the Carolinas; it flowers much earlier, with a smaller yellower bloom than other types. This east central Florida ecotype/Peninsular allozyme group seems to have the best ability to tolerate very wet conditions, where it may grow short pencil-like root structures similar to those produced by other swamp trees in warm climates. Superior resistance to drought, pests and wind is also noted. Some individuals retain their leaves all year unless a hard frost strikes. Places where it may be seen include Dr. Howard A. Kelly Park, Lake Eola Park, Spring Hammock Preserve, Big Tree Park and the University of Central Florida Arboretum.Ecology
Liriodendron tulipifera is generally considered to be a shade-intolerant species that is most commonly associated with the first century of forest succession. In Appalachian forests, it is a dominant species during the 50–150 years of succession, but is absent or rare in stands of trees 500 years or older. One particular group of trees survived in the grounds of Orlagh College, Dublin for 200 years, before having to be cut down in 1990. On mesic, fertile soils, it often forms pure or nearly pure stands. It can and does persist in older forests when there is sufficient disturbance to generate large enough gaps for regeneration. Individual trees have been known to live for up to around 500 years.All young tulip trees and most mature specimens are intolerant of prolonged inundation; however, a coastal plain swamp ecotype in the southeastern United States is relatively flood-tolerant. This ecotype is recognized by its blunt-lobed leaves, which may have a red tint.
Liriodendron tulipifera produces a large amount of seed, which is dispersed by wind. The seeds typically travel a distance equal to 4–5 times the height of the tree, and remain viable for 4–7 years. The seeds are not one of the most important food sources for wildlife, but they are eaten by a number of birds and mammals.
Vines, especially wild grapevines, are known to be extremely damaging to young trees of this species. Vines are damaging both due to blocking out sunlight, and increasing weight on limbs which can lead to bending of the trunk and/or breaking of limbs.