Taxodium ascendens seeds mature in November.Pond-cypress (Taxodium ascendens) is very similar to bald-cypress (T. distichum), and has been considered a variety of that species by some authorities. Most recent experts, however, now believe that pond-cypress is a distinct species. Pond-cypress has awl shaped or scalelike leaves which are closely appressed and overlapping on the twigs, whereas bald-cypress has linear leaves which spread out and are arranged in two ranks on opposite sides of the twigs. The branchlets of bald-cypress tend to spread horizontally outward, while those of pond-cypress are more ascending. Pond-cypress isn't as prone as bald-cypress to have knees, and when it does, they tend to be shorter and more rounded. Pond-cypress is usually more columnar than bald-cypress.
The two species are not always easy to tell apart. Hybridization probably occurs, and young, fast growing specimens of pond-cypress sometimes have leaves more like those of bald-cypress. Pond-cypress is generally a smaller tree, to 80 ft (25 m) or so in height. However, the National champion, in Pierce County, Georgia, is 135' (41 m) tall with a trunk diameter of 7.5 ft (2.3 m) - nearly as large as a big bald-cypress. The largest pond-cypress in Florida is 64 ft (19.5 m) tall and has a trunk diameter of 3.4 ft (1 m). It grows on the grounds of the Museum of History and Natural Sciences in Tallahassee.
Pond-cypress, Taxodium ascendens, occurs naturally in shallow ponds and wetlands along the southeastern U.S. coast from Virginia to Louisiana. Its distribution is smaller than that of bald-cypress, and it rarely grows along flowing streams and rivers or in floodplain bottomland swamps as does bald-cypress. Pond-cypress rarely is found at elevations above 100 ft (30 m).
Taxodium ascendens seeds
Pond-cypress seems to be more dependent on acidic soils than bald-cypress.
Light: Pond-cypress does its best in full sun.
Moisture: Like bald-cypress, pond-cypress grows well on dry upland sites even though it doesn't occur there naturally.
Hardiness: USDA Zones 5 - 11.
Propagation: Start the seeds in moist soil.
Lumbermen tend not to distinguish between this species and bald-cypress, although ecologists certainly do. According to Florida ecologist Dr. Katherine Ewel, pond-cypress tends to occur at higher densities than bald-cypress, on sites with slow to stagnant water, low nutrients, and occasional forest fires. Bald-cypress is more likely encountered at low densities, in places with moderate water flow, higher nutrient availability, and rare forest fires.
When pond-cypress grows on nutrient-poor or marly soils, as in some parts of the Everglades, Big Cypress Swamp and Tate's Hell in North Florida, they grow very slowly and usually remain stunted. Even very old trees may be no more that 6 ft (2 m) tall. These dwarfs are called "hat-rack" cypress.