Yellow Poplar
Lisa Frost (2007)

Liriodendron tulipifera

Yellow poplar, Liriodendron tulipifera, also known as the tulip tree, is found in the Matthews Parking circle and in front of Eaton Hall. It is actually not even a poplar, so let’s call it tulip tree. It grows quite quickly, but slows down with age (as all trees do); it is known for being tall and straight. Its leaves are unique—four lobes separated by round notches, and the flowers are greenish-yellow and tulip like. The flowers bloom in mid to late spring, but since they are not close to the ground they are not as celebrated as they might be. They can grow to be over 150 feet tall and seven feet in diameter, and 300 years old.

If grown in relatively open areas, they have a pyramidal shaped crown when young, and later a more oval shape. In old age the bark is thick and deeply furrowed, when young it is light gray-green and smooth. Twigs are red-brown with a shiny appearance, and have a sweet odor when broken. In the fall the leaves turn gold/yellow, and are more pronounced in the northern part of its range. Birds and small mammals feed on the seed, while deer browse saplings and flowers when they can reach.

Their natural habitat is in forest coves or lower mountain slopes, with rich well drained soils. They prefer well drained acidic soil. If the summer is especially dry, premature defoliation of the interior leaves, which turn bright yellow. It is relatively disease and insect tolerant. It is native to much of Eastern North America, from southern New England west through Michigan, south to Louisiana, and east to northern Florida. It is the state tree of Indiana, Tennessee, and Kentucky, and closely related to the Magnolia tree.

The tulip tree’s wood was used by Native Americans and European settlers to carve canoes. Today it actually is quite commercially valuable because it is versatile and can substitute for softwoods in furniture and framing construction. It also is treasured for its use as a honey tree, source of food for wildlife. The Onondaga, a Native American tribe, calls it Koyentakaahtas, or the white tree.

Interesting Stories:
In Perry County, Kentucky, there was a tulip tree reportedly over two thousand years old. It was nearly 250 feet tall and 27 feet around at it’s base. Eighty feet from the ground the first limbs spread their foliage. Efforts to save the tree went on for years, but it grew on land owned by the Ritter Lumber Company. People tried to make the land a state park, but were unsuccessful. On January 12, 1937 the lumber company cut the tree down. It turned out to be hollow, almost two thirds of the diameter, so much of the lumber broke apart when it fell.

November 1, 1998. Excerpts from: EUGA Scientists Engineer Yellow Poplar Trees That May Help Clean Up Toxic Mercury Pollution
University of Georgia researchers have genetically engineered yellow poplar trees giving them the ability to absorb toxic mercury from soil, convert the toxin to a relatively inert form, and release the converted matter as a vapor into the atmosphere. The research, the cover story in the October issue of the journal, Nature Biotechnology, suggests that trees are particularly promising for phytoremediation, the use of plants (phyto) to remedy (remediate) environmental pollution. The research was funded by the U.S. Department of Energy and UGA's Warnell School of Forest Resources.

"The yellow poplar is fast-growing, has an extensive root system and large leaves that provide plenty of surface area to release processed contaminants," said Scott Merkle, a forest biotechnologist at UGA. "All these make it attractive for remediation."

The bacteria detoxify metals on a small scale but, alone, can't possibly clean up the estimated $200 billion worth of heavy metal pollution in the U.S. Early attempts to insert the gene in plants were only marginally successful, so researchers had to extensively modify the gene for expression in plants, and finally trees.

In laboratory trials, yellow poplars with the gene showed a 10-fold increase over control trees in their ability to absorb toxic mercury ions and convert them to a vapor. In fact, Merkle said that merA trees not grown in mercury containing medium, actually performed poorly and looked weak and sickly compared to those grown in the mercury-spiked medium.

http://forestry.about.com/od/hardwoods/ss/tuliptree.htm