How the hardy bald cypress thrives in swamps and flooded areas
Trees are as close to immortality as the rest of us ever come.
-- Karen Joy Fowler
Author Karen Joy Fowler has it right. When it comes to "immortal" trees in Illinois and the Eastern U.S., none have lived longer than the bald cypress (Taxodium distichum).
Before we get to this species' longevity, we'll cover some other surprising qualities of the bald cypress.
Conifer or evergreen?
These two words are not synonymous. Not all conifers are evergreen. Keep in mind that evergreen trees do drop their needles or leaves during the year. They just don't do it all in the same season like most deciduous trees do.
Conifer means that these kinds of trees -- pine, spruce, fir, cypress -- all produce seeds in cones.
Bald cypress is one of the few deciduous cone-bearing trees. I am writing this article in late October, and cypress needles are just starting to turn color like their broad-leaved compatriots. The feathery cypress needles will turn colorful shades of yellow, bronze, or cinnamon during the fall.
I say feathery for a reason. A bird's feather is flat with minute filaments, called barbs, coming out on either side of a main shaft. Similarly, cypress twigs have their individual needles growing on either side of the stem.
This flat or two-ranked arrangement differs from pines, which have needles in clusters, or spruces, which feature single needles that circle the twig. Since the small cypress needles are only about half an inch long, they don't require much raking in the autumn. It's not too hard to imagine how this sometimes needleless conifer earned the "bald" moniker.
Swamps are wetlands dominated by a type of woody plant. In Florida, you have mangrove swamps. In northern Michigan and Wisconsin, you have cedar swamps. In southern Illinois, we have cypress swamps.
Historically, cypress swamps could be found across the southeastern U.S., along the coastal plain to the mid-Atlantic states, and in the Mississippi River drainage basin to the southern tip of Illinois.
Anyone who cares for trees knows that flooding can kill many types of trees. Waterlogged soils prevent the tree's roots from getting the air they need. Swamp-dwelling cypress trees have an effective and distinctive way of meeting this challenge. Believe it or not, they have "knees" -- also known as pneumatophores to botanists.
These knees grow up from the roots and protrude above the water, facilitating access to oxygen. Some reach heights of eight to 10 feet. It is believed that the average water depth determines the height of knees.
Mangroves, mentioned earlier, also sport pneumatophores. Be aware, the aeration hypothesis is just the most popular explanation for pneumatophores. Other ideas include nutrient acquisition, carbohydrate storage, and mechanical support. Of course, the knees could provide the trees with a variety of services.
Back to mechanical support -- an argument can be made that such large, wetland trees need strong anchors. How large? Bald cypress can grow to more than 100 feet tall and have a trunk diameter of up to eight feet. Be aware that the base of the trunk is often swollen.
Now imagine being an early explorer marveling at these towering, primeval, leafless trees.
When foresters are involved with trees of this size, wood products are not far behind. In addition, bald cypress is famous for resisting decay. Cypress lumber is so enduring that it is known as "wood eternal." It has been used for boats, river pilings, bridges, decking material, fence posts, veneer, doors, and interior trim. Not surprisingly, many bald cypress forests have been cut down.
This raises a question: How do you cut a huge tree down in a bayou? In 1889, Dr. Charles Mohr watched two loggers in a little boat do just that. He wrote, "it was astonishing to witness the steadiness and celerity with which they performed their work, considering the instability of their footholds in the narrow boats."
Living historical markers
If bald cypress trees are spared the ax or saw, they can live for a millennium or two.
The largest and oldest bald cypress in Illinois grows in a swamp along the Cache River in the southern tip of the state. Getting a precise ring count has proved difficult, but this cypress is at least 1,000 years old.
Heading east to North Carolina, you'll find the Three Sisters Swamp along the Black River. Growing there is a bald cypress that is at least 2,624 years old. It is the oldest known wetland tree species, and the oldest living tree in eastern North America.
According to a Smithsonian article, this cypress was alive "when Nebuchadnezzar II built the Hanging Gardens of Babylon, when the Normans invaded England, and when Shakespeare first set quill to paper." It sort of makes a centuries-old oak look like a young whippersnapper.
From the bayous to the 'burbs
As many homeowners and urban foresters have discovered, you don't need to be in the South or in a swamp to have success growing a bald cypress tree. Obviously, if you have a wet area in your yard, bald cypress is the tree for you. They will also thrive on well-drained land. In fact, the species is part of many metro streetscapes. Cypresses can be found in Chicago, New York, and Ottawa, just to name a few examples. Many can be found growing here in the Northwest suburbs.
When planted on land, their famous knees are few and far between. Remember to allow plenty of room for what can become a large tree. They do like sun and seem to prefer slightly acidic soils.
Bald cypress is not only growing in North America. Cypress trees have been cultivated and planted across Europe starting in the mid-17th century.
This brings us to the subject of cultivated varieties, which are commonly called cultivars.
These varieties are bred and raised in greenhouses and nurseries. Specimens are selected to grow in a particular manner or for foliage of a desired color. Then garden centers can show a tree that has unusual foliage or another one which has "weeping" branches. Many bald cypress cultivars were created right here in Illinois. Each cultivar comes with a trade name.
A partial list of these cypress cultivar names include Prairie Sentinel, Shawnee Brave, and, my favorite, Monarch of Illinois.
Wood really eternal
Before there was a state of Illinois or any humans on the continent, there were bald cypress trees. Not surprisingly, petrified bald cypress logs have turned up in some western national parks.
More unexpectedly, fossil bald cypress logs turned up under Baltimore when they were digging the foundation for their new football stadium. Remember that bald cypress trees were growing in swamps 100 million years ago, long before the Baltimore ravens or most modern birds had evolved.
As you might have guessed, we have planted bald cypress trees here at Stillman and they are doing well. Our young cypress trees are growing while red-tailed hawks and other avian raptors soar overhead. I can't help but think about how this type of tree kept company with the long-extinct velociraptors. Wood eternal, indeed.
• Mark Spreyer is executive director of the Stillman Nature Center in Barrington. Email him at email@example.com.