Bald Cypress (Taxodium distichum)
Identifying Features
Plant Family:Cupressaceae
Native Range: Southeastern United States
Leaf: deciduous, short needles are flat in two ranks, needles are on twiglets that attach to stem in a spiral
Twig and Bud: twig brown or copper with knobby leaf scars and sessile buds
Flower, Fruit and Seed: flower purple and insignificant, cones are round and wrinkled
Bark: red-brown to gray with thin vertical exfoliating strips
Shape and Mature Height: pyramidal, mature height of 50-70 feet
Garden Value and Considerations
Bald cypress are coniferous trees native to the swamps and rivers of the Southeastern United States. They prefer moist, acidic, sandy soils, but tolerate wider soil conditions including clay soil. They can handle soil moisture ranging from well-drained to wet soil in standing water. Bald cypress trees growing in wet conditions will develop widened trunk bases and roots with woody knees.
The name bald cypress eludes to the deciduous nature of these trees, a trait not typical of many other conifers. The needles display shades of orange and cinnamon in the fall. They drop beneath the trees creating a colorful mulch.
Bald cypress trees offer many ornamental properties including their pyramidal shape, striking fall foliage, exfoliating bark, fluted trunks and notable knees. Bald cypress can be used as a vertical accent or stand-alone specimen in the landscape. They work well in large lawns and near water, or can be used as a deciduous hedge or street tree. Bald cypress trees need full sun to part shade.
Notes
One of the most unique features of bald cypress trees are the knees that rise up from the roots. Only Taxodium species and Chinese Swamp Cypress Glyptostrobus pensilis produce these woody root projections. The growth and size of the knees correlates to the extent of water exposure and the age of the tree, with larger knees developing on older specimens with greater time in or near water. Similarly, the broad conical root flares that may develop on bald cypress trees is influenced by the duration and depth of water exposure.
The reason for the knees on bald cypress trees is a mystery that has been the subject of research and speculation for nearly two hundred years. Some of the proposed theories about the function of the knees include providing the roots exposure to air, helping to anchor the trees against high winds, or providing a back-up food source for the trees. A definitive reason has yet to be determined and it may be possible that the knees developed in response to a pressure the trees no longer face.
