DISCOVERING EVERGLADES PLANTS AND ANIMALS (continued)

Air Plants

Long before you have learned to distinguish the major plant communities, you will be aware of the air plants—or epiphytes—that grow so profusely in Everglades. Epiphytes are non-parasitic plants that grow on other plants, getting their nourishment from the air. Best known is Spanish moss, which festoons the trees of the coastal South from Virginia to Texas; this plant is used by the swallow-tailed kite in constructing its beautiful nest. Despite its name, Spanish moss is actually a member of the pineapple family—the bromeliads. Bromeliads are the most conspicuous of the park's air plants. The epiphytic orchids, though less common, are celebrated for their beauty; their fame, unfortunately, has led to their widespread destruction. There are also epiphytic ferns, trees, and vines; and one cactus, the mistletoe cactus, has taken to the air.

Air plants are highly specialized for making a living under crowded conditions; there are more than 2,000 species of plants competing for sun and water in southern Florida. The epiphytes have adapted to the problem of space by growing on other plants. Their roots, although they absorb some water and minerals, are primarily anchors. Living in an atmosphere that fluctuates between drought and humidity, they have evolved several water-conserving tricks. Some have a reduced number of leaves; others have tough skins that resist loss of water through transpiration; still others have thick stems, called pseudobulbs, that store moisture. The bromeliads are particularly ingenious: many have leaves shaped in such a way that they hold rainwater in vaselike reservoirs at their bases. Mosquitoes and tree frogs breed in these tiny reservoirs, and in dry periods many aboreal animals seek the dew that collects here.

COMMON BROMELIADS. (click on image for an enlargement in a new window)

Most of the orchids and bromeliads grow in the dimly lit tropical hardwood hammocks and cypress sloughs. A few species, however, having adapted to the sunlight, live on dwarf mangroves and the scattered buttonwoods, pond apples, willows, and cocoplums of the glades. The butterfly and cow-horn orchids are sun lovers, as are the twisted, banded, and stiff-leaved bromeliads. All have adapted to the sun with dew-condensing mechanisms or vases at the bottom of the clustered leaves.

One tree, the strangler fig, starts as an epiphytic seedling on the branches of other trees. Eventually, however, it drops long aerial roots directly to the ground or entwines them about the trunk of the host tree—which in time dies, leaving a large fig tree in its place.

Of all Everglades plants, the epiphytic orchids are most fascinating to man—a fact which largely explains their decline. Of some 50,000 species around the world (the orchids being one of the largest of plant families), the park has only a few. Fire, loss of habitat due to agriculture and construction, and poaching by both commercial and amateur collectors have brought about the extermination of some and have made others exceedingly rare. Some are rare because of special life requirements. For example, a few must live in association with a certain fungus that coats their roots and provides specific nutrients.

The largest orchid in the park is the cowhorn, some specimens of which have weighed as much as 75 pounds. Unfortunately, this orchid has been a popular item for orchid growers and collectors and is becoming rare in Florida. Poachers have practically eliminated it from the park. Recently Boy Scout friends of Everglades salvaged many orchids from hammocks about to be bulldozed for the jetport. By laboriously tying them to trees in the park, they assured the survival of the plants.

SHOWY ORCHIDS OF THE HAMMOCKS AND TREE ISLANDS. (click on image for an enlargement in a new window)

The night-blooming epidendrum is perhaps the most beautiful of the park's orchids. It is widespread and fairly common in Everglades, occurring in all ecosystems. Flowering throughout the year, it bears its white, spiderlike blossoms, 2 inches across, one at a time. It is especially fragrant at night—hence its name.

Epiphytic orchids have the smallest seeds of any flowering plants. Dustlike, they travel far and wide on the air; it is believed that over eons all species of Florida orchids arrived on the wind from South America and the West Indies.

The giant wildpine is a spectacular bromeliad that grows on the sturdy limbs of buttonwoods, spreading to 48 inches and developing a flower stalk 6 feet long.

Of the approximately 20 species of epiphytic ferns in the park, the most common is the curious resurrection fern. Sometimes called the poor man's barometer, it has leaves that in dry weather curl under and turn brown but with the coming of rain quickly unfold and turn bright green, making instant gardens of the logs, limbs, and branches on which they grow.

Watch for the air plants (as well as the trees and other wildflowers) that have been labeled along the trails and boardwalks. You will be able to examine some of them closely—but leave them unharmed for future visitors!