Bald cypress

Taxodium distichum
Family: Cupressaceae

Natural Historybaldcypress branch
Leaves and seed cone of bald cypress
Photo credit: Larry Korhnak, University of Florida

Bald cypress is a long-lived, deciduous wetland species that grows along rivers, streams, and creeks as well as in swamps with slow moving water. It is a legendary tree of the Deep South known for its "knees," moss-draped crown, and buttressed trunk. It can grow 100-150 feet tall and 3-6 or more feet in diameter and can live up to 600 years. Some river edges still have stumps of giant cypress trees that were logged in the early 1900s. A few old giants live in parks across Florida. The crown is open and narrowly pyramidal. Old-growth bald cypress has a flattened crown usually dangling with Spanish-moss (Tillandsia usneoides). This tree has a very distinctive root system which consists of numerous "sinkers" that provide anchorage, which are supported by a wide-spreading, lateral system of shallow roots.

Bald cypress can be easily confused with pond cypress (Taxodium ascendens) which is closely related. Careful attention to detail can differentiate these two species. Pond cypress has smaller, scale-like leaves pressed on the twigs. A twig of pressed pond cypress leaves resembles a pine needle pointing up or out from the branchlet. Bald cypress leaves are linear and featherlike, and the twigs hang down looking more pendulous than pond cypress twigs and leaves. Also, pond cypress tends to occur in still-water wetlands rather than in the flowing-water wetlands of the bald cypress habitat.

"Knees" are present in both pond cypress and bald cypress root systems when they are growing in water. Cypress "knees," or pneumatophores, are cone-shaped extensions of the root system protruding from the ground. The purpose of these knees remains a mystery. Some scientists believe that these structures provide structural support and may be the tree's way of obtaining oxygen for the roots during flooded conditions. Other scientists believe the knees may have evolved as a form of defense against the footsteps of ancient large herbivores.

Habitat & Range

The bald cypress is typically a tree of permanent swamps and river channels and floodplains, where it occurs in extensive pure stands or occasionally with water tupelo. On somewhat higher ground it is found with bottomland hardwoods such as American elm, red maple, green ash, sweetgum, and some oaks. It grows best on deep, moist, sandy loams, but it is rarely found on such sites because of its inability to compete with hardwoods. It occurs in the coastal plains along the Gulf and the Atlantic Ocean and north up through the Mississippi River Valley.

Wildlife Use

Bald cypress is a very important tree in the swampland ecosystem. It is valuable for wildlife food and cover. Canadian geese migrating to the south feed on the seeds. Swamp rabbits and other birds, such as Florida cranes and ducks, also feed on bald cypress. White-tailed deer escape to the cover of bald cypress swamps during hunting season. Many animals find shelter in and around the base of large old-growth trees.

Human Use

Because of the unique shape of the base of each trunk, artists have created clocks, furniture, and wall décor from the cross-sections of this tree. In the landscaping industry, bald cypress is planted for its ornamental beauty. Old-growth heartwood is especially desired in the timber industry. It is especially used in the construction of docks, bridges, silos, tanks, caskets, and general millwork because of its durability and resistance to rot. However, lumber use of bald cypress has declined because it is a slow-growing tree. It is harvested from wetlands, and the population of mature trees is much smaller than in the past. The resin extracted from the cones is used locally as an analgesic for lesions of the skin.


 

Identifying Characteristics

Size/Form: Bald cypress is a large tree which may reach heights of 100 to 150 feet. The trunk is usually buttressed and fluted at the base in extremely wet areas. It has a pyramidal-shaped crown when it is young that gradually becomes flat-topped with age. When growing in water, it has shallow roots that often arise from the soil in the shape of cones called pneumatophores, or "knees."
Leaves: Individual leaves are narrow and linear, with a sharply pointed tip. Each leaf is about one-eighth of an inch wide and ½" to ¾" long. The leaves are alternate and 2-ranked, meaning that they spread out on either side of the branchlet like a feather. The foliage is deciduous in the fall, but it is the branchlets (rather than the individual leaves) that drop off the trees.
Twigs: The terminal twigs are light green through the growing season, becoming reddish-brown during the winter.
Bark: The reddish brown to ashy gray bark is thin and peels in narrow vertical strips.
Pollen cones: Pollen is produced in small, purplish-brown pollen cones on long "threads" that dangle from the tips of the branches.
Seed cones: Seeds are held in a spherical cone that is about ¾" to 1" in diameter. The cones are wrinkled, with club-shaped, leathery, yellowish-brown scales and can be solitary or in clusters. Upon maturity the cones become woody and the shield-shaped scales that originally fit closely together begin to shrink and pull apart, allowing the seeds to escape. The seeds are irregularly 3-angled and 3-winged.
Similar Trees on the Florida 4-H Forest Ecology Contest List:
  • None. The foliage on this tree should make it easy to recognize.

 

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