Posted: December 13, 2021
With its many delightful qualities, tulip poplar trees deserve renewed consideration from property owners who have sufficient space for planting them.
Leaf – Fall leaf of the poplar tree, Liriodendron tulipifera Photo by: Melody J. Kraus
During the fall, a tall straight tree covered in yellow foliage stands brightly and boldly in the forest, along with the reds of the maples and the copper browns of some oaks. It is the Liriodendron tulipifera. Leirion is Greek for lily and dendron is Greek for tree, while tulipfera means tulip bearing. Common names for it include lyre tree, old wife's shirt, saddle tree, tulip poplar, tulip tree, tulip tree magnolia, white-poplar, whitewood, yellow poplar and yellow wood. Some of these vernacular terms derive from its tulip shaped leaves or its greenish-yellow hardwood. However, this tree is not related to lilies, poplars or tulips; instead, it belongs to the magnolia (Magnoliaceae) family. Only two species exist: one native to the eastern half of the United States and the other growing in central China.
Even without its obvious fall foliage, the poplar tree is distinctive in the forest. Perhaps, the most unique trait is a nearly perfectly straight trunk. Furthermore, it is the tallest hardwood tree in mixed species forests from central Pennsylvania westward to Illinois, southward to northern Florida and in all states in between. In fact, it is the state tree of Indiana, Kentucky and Tennessee. For a tree, it is "fast growing'" requiring 50 years to reach its average maximum height of 120 feet, but this growth slows over time. The species has been known to reach 200 feet in height with a trunk diameter of 8 to 10 feet and an absence of lower branches. According to the Monumental trees website, the tallest tulip tree in Pennsylvania is located at Longwood Gardens with a height of 50.90 meters and is estimated to be 400 years old. The average tree lives 250 years.
Despite being a native, the poplar has a more limited wildlife value than other indigenous trees, such as cherries, oaks and willows, which can support 1400 or more species of caterpillars among the three of them, according to Doug Tallamy, the author of Bringing Nature Home. However, the poplar is favored by the larvae of the Tiger Swallowtail (Papilio glacus), the Spicebush Swallowtail (Papilio troilus) and the Viceroy (Limenitis archippus), which consume the leaves. A specialist butterfly Callosamia angulifera, aka the Tulip Tree Silkmoth, uses the tree as its sole host plant, which is vegetation upon which a living thing lives, eats and reproduces exclusively.
The blossoms, which appear in April and May at approximately 15-20 feet above the ground, are pollinated by bees, particularly honeybees. The colorful center leads them to the nectar, which hummingbirds, as well as other birds, and butterflies consume. In addition, bees make a gourmet honey from the blossom, which is dark in color, but mild in flavor, and is valued in cooking.
The flowers develop into fruits, which become cone-shaped masses of multiple seeds called samara, which contain a seed at one end and have a wing-like body shape to assist dispersal by the wind. One by one these seeds begin to fall in autumn and continue throughout the winter, providing food for birds. The cores of the samara cones persist on the branch tips after all the seeds have disappeared.
In addition, the poplar has environmental value with its deep and extensive root system which aids in retaining soil. The leaves fall to the ground, becoming litter, which provides a hiding and overwintering place for insects and their eggs. As the leaves decompose, old soil is enriched and new soil is created.
Furthermore, the tulip tree has value for humans. The earliest known use of this tree involves collection of the leaves and the inner bark for medicinal purposes. Specifically, the Cherokee made the leaves into a poultice for sores. Other Native Americans brewed tea from the bark to cure fever and indigestion. European colonists used the tree as remedies for such ailments as malaria and toothaches. By 1787, an extract made from the bark and roots of the tree was used by colonists as a fever reducer for rheumatic fever. From 1830-1880, the U.S. Pharmacopoeia listed it as a stimulant tonic with diaphoretic (causing sweating) properties to treat intermittent fevers. Finally, in 1886 the active ingredient in the bark was isolated: an alkaloid named tulipferine.
Due to its height and straightness, this tree has been recognized for its building properties. The Woodland Native Americans made dugout canoes, leading to the nickname canoe tree. This craft was copied by European settlers. In fact, according to the Audobon Society, a 60-foot long canoe was made by Daniel Boone using wood from the tulip poplar.
The early North American explorers noted the shape and size of the poplar tree and soon discovered its usefulness in building cabins and ships, as well as using the trunks to form ship masts. Large scale harvesting of this tree began after the end of the Civil War as more and more woodworkers saw it as a plentiful lumber source.
Unlike other hardwoods, the poplar is lightweight and easy to shape, yet it retains its strength. It has been and continues to be utilized in general construction for lumber, plywood, and paper pulp, as well as for more specific items, such as flooring, furniture, pallets, toys, veneer, and musical instruments, including pipe organs.
Because of its straight tall trunk, noticeably shaped 4 lobed leaves and beautiful flowers, this tree has been planted as a shade tree in the United States. The U.S. Forest Service (USFS) recommends planting it on large lots, so the roots have room to grow to maturity and approximately 10 to 15 feet from roads. Its unique characteristics caused this species to be sent to Europe for cultivation, becoming one of the most popular American trees grown in France and England.
The poplar tree has distinctive properties noted and utilized by North American inhabitants in the past and present. The majority of them still apply today. However, this native hardwood has become overlooked in recent years as a specimen tree in yard. With its many delightful qualities, tulip poplar trees deserve renewed consideration from property owners who have sufficient space for planting them.
Melody Kraus is a Penn State Master Gardener from Adams County. Penn State Cooperative Extension of Adams County is located at 670 Old Harrisburg Road, Suite 204, Gettysburg, phone 334-6271.
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