Taxodium distichum

Taxodium distichum (bald cypress, swamp cypress; French: cypres chauve;
cipre in Louisiana) is a deciduous conifer in the family Cupressaceae. It is native to the southeastern United States. This tree is hardy and resilient, and can adapt to any soil type, wet, salty or dry. Its lacy, russet-red leaves are a hallmark of this tree.

This plant has some cultivated varieties and is often used in groupings in public spaces. Common names include bald cypress, swamp cypress, white cypress, tidewater red cypress, gulf cypress and red cypress.

In 1963, Louisiana designated the bald Cypress as its official state tree.

Description

Taxodium distichum is a large, slow-growing, and long-lived tree. It typically grows to heights of 35-120 feet (10-40 m) and has a trunk diameter of 3-6 feet (0.9-1.8 m).

The main trunk is often surrounded by cypress knees. The bark is grayish to reddish brown and thin with a fibrous texture. It has a vertically interwoven pattern of shallow furrows and narrow ridges.

The needle-like leaves are

1/2 to 3/4 inch (1.3 to 1.9 cm) long and are simple, alternate, green and linear, with entire margins. The leaves turn yellow-brown in autumn. The bald cypress drops its needles each winter and then grows a new set in spring.

This species is monoecious, with male and female flowers on a single plant forming on slender, tassel-like structures near the edge of branchlets. The seeds are ripe in October and the tree blooms in April. The male and female strobili are produced from buds formed in late autumn, with pollination in early winter, and mature in about 12 months. Panicles measuring 4-5 inches (10-13cm) in length are used to produce male cones. Female cones are round, resinous and green while young. As the tree matures, they become hardened and brown. They are globular and 2.0-3.5 cm (3/4–1+3/8 in) in diameter. There are 20-30 spirally arranged four-sided scales that each bear one, two or occasionally three triangular seeds. Each cone has 20-40 large seeds. The cones disintegrate at maturity to release the seeds. The seeds are 5-10 mm (3/16–13/32 in) long, the largest of any species of Cupressaceae, and are produced every year, with heavy crops every 3-5 years. The seedlings have three to nine, but usually six, cotyledons each.

The bald cypress grows in full sunlight to partial shade. This species grows best in wet or well-drained soil but can tolerate dry soil. It is moderately able to grow in aerosols of salt water. It can grow in all soil types, including acid, neutral, and alkaline. It can also grow in saline soils. It can tolerate atmospheric pollution. The cones are often consumed by wildlife.

The tallest known specimen, near Williamsburg, Virginia, is 44.11 m (145 ft) tall, and the stoutest known, in the Real County near Leakey, Texas, has a circumference of 475 in (39 ft). The National Champion Bald Cypress is recognized as the largest member of its species in the country and is listed as such on the National Register of Champion Trees by American Forest. The National Champion Bald Cypress can be found in Cat Island Nation Wildlife Refuge near St. Francisville. It stands 96 feet tall and 56 feet wide and is approximately 1,500 years of age. The oldest known living specimen, found along the Black River in North Carolina, is at least 2,624 years old, rendering it the oldest living tree in eastern North America.

Habitat and Range

The native range extends from southeastern New Jersey south to Florida and west to East Texas and southeastern Oklahoma, and also inland up the Mississippi River. The Southeast was once dominated by ancient bald cypress forests with some trees older than 1,700 years. The range had been believed to extended north only as far as Delaware, but researchers have now found a natural forest on the Cape May Peninsula in southern New Jersey. It can also be found outside of its natural range.

The largest remaining old-growth stands are at Corkscrew Swamp Sanctuary, near Naples, Florida, and in the Three Sisters tract along eastern North Carolina’s Black River. Some Corkscrew trees exceed 40m in height and are approximately 500 years old. In 1985, the Black River trees were cored by dendrochronologist David Stahle from the University of Arkansas. He found that some began growing as early as 364 AD. Stahle returned to the region in 2019 and discovered that a tree was dated to 605 B. C. This tree is the ninth-oldest in the world.

This species is native to humid climates where annual precipitation ranges from about 760 mm or 30 inches in Texas to 1,630 mm or 64 inches along the Gulf Coast. Although it grows best in warm climates, the natural northern limit of the species is not due to a lack of cold tolerance, but to specific reproductive requirements: further north, regeneration is prevented by ice damage to seedlings. Larger trees are able to tolerate much lower temperatures and lower humidity.^{[citation needed]}

Scuba divers found an underwater cypress forest in 60 feet of water, a few miles off the coast from Mobile, Alabama. The trees in the forest cannot be radiocarbon dated, which indicates that they are older than 50,000 years and lived during the first glacial period of the last Ice Age. The forest of cypress trees is very well preserved. When samples are taken, they still smell fresh. The site is being studied by a team that has yet to publish its findings in a peer-reviewed journal. One possibility is that hurricane Katrina exposed the grove of bald cypress, which had been protected under ocean floor sediments.

Ecology

The seeds remain viable for less than one year, and are dispersed in two ways. The first is by water: The seeds float on water and then move to shore or disappear. The second is caused by wildlife: squirrels eat the seeds but sometimes drop scales from the cones. The seeds do not germinate in water and seldom germinate on well-drained soils. Seedlings usually become established after being continuously saturated for up to three months. Seedlings need to grow rapidly after germination to avoid flooding. They often reach heights of between 20 and 75 cm, or even 100 cm in fertilized nursery environments, within their first year. Seedlings die if inundated for more than about two to four weeks. Natural regeneration is therefore prevented on sites that are always flooded during the growing season. While stump sprouts and vigorous saplings can produce viable seeds, most specimens don’t produce seed until they reach 30 years of age. In good conditions, bald cypress grows fairly fast when young, then more slowly with age. Trees can reach heights of 3 m within five years, 21 years in 41 years and 36 years in 96 years. However, height growth has stopped largely by the time they are 200 years old. Some people can live for over 1000 years. Determination of the age of an old tree may be difficult because of frequent missing or false rings of stemwood caused by variable and stressful growing environments.^{[citation needed]}

Bald cypress trees growing in swamps have a peculiarity of growth called cypress knees. These are woody projections from the root system project above the ground or water. They were once believed to have been there to supply oxygen to roots that grow in low-dissolved oxygen water like mangroves. There is little evidence to support this. In fact, the oxygen content of the roots of swamp-dwelling species that have had their knees removed does not decrease and they continue to thrive. Structural support and stabilization are another possible function. Bald cypress trees growing on flood-prone sites tend to form buttressed bases, but trees grown on drier sites may lack this feature. Buttressed bases and a strong, intertwined root system allow them to resist very strong winds; even hurricanes rarely overturn them.

Many agents can cause damage to T. distillum trees. The main damaging (in some cases lethal) agent is the fungus Lauriliella taxodii, which causes a brown pocket rot known as “pecky cypress.” It usually attacks the heartwood of living trees from the crown to the roots. A few other fungi attack the sapwood and the heartwood of the tree, but they do not usually cause serious damage. Trees can be seriously damaged by insects like the cypress fleabeetle ( Cystena marginalis), and the bald-cypress leafroller( Archips Goyerana). These insects destroy leaves, cones, and bark. Nutrias can also cut and unroot young bald-cypress seedlings. This can sometimes result in the death of entire plantations.

The Indiana Department of Natural Resources designated T. Distichum as an endangered state plant in 2002. Globally, the species is listed as of Least Concern by the IUCN.^{[citation needed]}

Taxonomy

The closely related Taxodium ascendens (pond cypress) is treated by some botanists as a distinct species, while others classify it as merely a variety of bald cypress, as Taxodium distichum var. imbricatum Croom. Croom. A few authors also treat Taxodium mucronatum as a variety of bald cypress, as T. distichum var. mexicanum Gordon, thereby considering the genus as comprising only one species.