Coniferophytes (Conifers) in the Christopher B. Smith Preserve

Coniferophyte Characteristics: Conifers range is size from shrubs to very large trees. Their leaves are needle or scale-like. As a conifer ages, its stems continue to expand in width and length. Older stems and roots become woody. Conifers reproduce by seeds, but the seeds do not have shells like magnoliophytes (flowering plants). Instead, the seeds are naked inside cones.

During the Mesozoic Era (time of the dinosaurs), conifers dominated the earth.

Interactions in the Smith Preserve: Like other plants, conifers convert energy of sunlight to energy other organisms can use. The conversion process is photosynthesis and the energy conifers produce is distributed to animals through the food web. Also during photosynthesis, conifers produce oxygen. In addition, conifers provide habitat for other organisms.

 
Phylum
Family
Species Name
Common Name
Coniferophyta
Pinaceae
Pinus elliottii densa
Coniferophyta
Cupressaceae
Taxodium distichum

 

 

Pinus elliottii densa

Southern Florida Slash Pine

Pinus elliottii densa is a native, fast-growing, perennial member of Family Pinaceae. It is a hard yellow pine that lives up to 200 years. Trees grow 18 to 30 m. in height with trunk diameters .6 to .8 m. The leaves (needles) are in clusters of two or three and are 18 to 24 cm long.

Its common name "Slash pine" is based on slash habitat (swampy ground overgrown with trees and bushes). Each tree produces both male and female cones. Male cones develop as small knobs near the base of vegetative buds. As shown below in the left photograph, they are usually in clusters of 12 or more and arranged in a spiral around the base of the current year's branches. They are purple and five cm long when pollen is shed. The female cones (shown below at right) occur singly or in clusters and are most abundant on primary and secondary branches in the upper crown. When female cones are fully developed, they are glossy red-brown, five to 15 cm in length, and have short thick prickles on each scale. At different times on the same tree, male cones shed pollen and female cones are receptive to being pollinated. Cross-pollination among trees occurs by wind.

The most serious disease of slash pine is fusiform rust caused by the fungus Cronartium quercuum. A variety of insects including weevils and other beetles, webworms, and sawflies invade slash pine. Some of these insects feed on the bark, while others defoliate. With a large enough infestation, a tree wilts and dies.

The use of slash pines for wood, turpentine, and resin is one of the oldest industries in the United States.

Slash pine seeds are food for a variety of birds and small mammals. The dense foliage provides protective cover for many wildlife species.

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Taxodium distichum

Bald Cypress

Taxodium distichum is a native, deciduous conifer in Family Cupressaceae (Cypress Family). It grows in saturated soils and soils seasonally inundated by freshwater. It is a large tree, reaching 25 to 40 m or more and with a trunk diameter of 2 to 3 m, rarely to 5 m. In the Smith Preserve, young cypress trees have been planted along the edge of the filter marsh.

Taxodium distichum bark is gray-brown to reddish-brown and has a stringy texture. As seen in the third photograph above, the leaves spiral on the stem but twist at the base so they lie parallel to one another. They are one to two cm long and one to two mm wide. Being deciduous, the trees lose their leaves in the winter. This characteristic is the origin of its common name "bald cypress."

The tree has both male and female reproductive organs. The male structures are catkins. A catkin is two mm in diameter, slender, purple, and a drooping cluster seven to 13 cm long. Pollen is shed from the catkins in March and April. The female cones (seed cones) are green, but mature to brownish-purple. They are globe-shaped and 13 to 36 mm in diameter. Each cone has nine to15 spirally arranged, four-sided scales. Each scale has one to two triangular seeds. As the cones mature, they disintegrate, releasing the seeds, each five to ten cm long.

In older trees, the main trunks are surrounded by cypress knees. These are woody projections from the root system that project above the ground or water. Their function is thought to be for support and stabilization.

Bald cypress are used by wildlife in a variety of ways. Squirrels and a many bird species eat the seeds. Large old bald cypress trees provide nesting sites for bald eagles and ospreys. Epiphytes (Spanish moss and resurrection fern) often cling to its bark. Birds forage these plants. Warblers find nesting cavities in old decaying cypress knees. Fish spawn near the roots.

Since bald cypress wood resists decay, it is used in a variety of building materials. Recently, it has become a popular wood for mulch.

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© Photographs and text by Susan Leach Snyder (Conservancy of Southwest Florida Volunteer), unless otherwise credited above.

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