Plant Profile: Native Orchids By Craig Huegel Reprinted from The Understory, Jun.-Jul. 1999 Florida has more native orchid species than any other state in the nation. Because of our geologic history, our climate, and our proximity to the Caribbean and tropical America, we have a great diversity of species. Many of these are found nowhere else in the United States. Unlike popular b belief, orchids are extremely hardy plants. If you grow orchids at home, you will find that they can survive a good deal of "mistakes" or "mismanagement" before giving up the ghost. On the other hand, they are extremely habitat sensitive and very difficult to establish by seed. Orchid species occur only where their habitat needs are met, and these needs are often very narrowly defined. When an orchid is pollinated, its seed capsule will contain hundreds of thousands of seeds, sometimes millions. Each seed is exceedingly small. As the capsules ripen and split, the seeds are released and carried as dust through the atmosphere. There is a constant "rain" of orchid seed being deposited in Florida. This explains how a great many tropical species find their way here. When they find the "right" conditions, they take hold. Areas like the Fakahatchee Strand are famous for their diversity of orchids because they provide a tropical environment. Species come and go naturally in these areas as conditions change. Of course, human-caused habitat changes have huge impacts. Orchid seeds do not have endosperm--the part of the seed that provides energy to the embryo at the time it sprouts and develops a root system capable of feeding it. Because of this, orchid seeds die very quickly after they sprout unless they land in just the right place. Their new roots must immediately find the correct fungi to form a relationship that will supply them with nutrients. Without it, they starve. They also need just the right amount of sunlight and moisture. This, too, differs by species. We have orchids that only grow in very arid sunny conditions as well as those that are tropical. Orchids generally are very slow to reach maturity. Although some are adapted to a faster rhythm, most take years (up to about 7 years) before they reach an age when they first flower. Many things can happen to them during that period to prevent them from ever flowering. Freezing temperatures kill many of the tropical orchids that inhabit the state. Severe changes in weather can have significant impacts too. Heavy winter rains, like those during the El Niño year of 1998, excessive temperatures or drought, and changes in humidity that may come from deforestation of nearby lands, can be disastrous. Problems also may arise from herbivores. Squirrels and other rodents, as well as deer, can consume entire plants or wipe out years of growth in short order. Most orchids are relatively immune from insects and disease, but these, too, can take a toll under certain conditions. If an orchid reaches sexual maturity, there is no guarantee it will flower and produce seed. Flowering is greatly influenced by environmental conditions. When conditions are not right, few if any flowers will be produced. Flowers are easily damaged, too. Insects and other herbivores may consume them. Environmental conditions may cause them to abort or to wither. Pollination in most species is very complex and relies on specialized insects. Orchid pollen is not carried in the wind. It is often moved by native bees, and many orchids have a relationship with just one species, or a small group of species, capable of pollinating them. Changes in an area's insect population can have significant impacts on orchid populations. There are essentially two types of orchids, terrestrial and epiphytic. As the names imply, terrestrial orchids grow in the ground while epiphytic species attach themselves to something above the ground. Epiphytic orchids often grow on the branches or trunks of trees and shrubs, but some species have adapted to growing on rocks or on cliffs. Orchid roots are very efficient in absorbing water and nutrients. They are covered by a spongy material called velamen that essentially acts as a sponge. Few orchids occur in saturated substrates. Their roots need to "breathe" to survive. Overwatering kills more orchids than drought. Many orchids have "bulbs" and leathery leaves. These are adaptations that allow them to conserve water and energy. There are a great many interesting and beautiful orchids that occur in our region and many of these bloom during the months of spring. A few, such as some of the Spiranthes and Habenarias, are relatively common in the right conditions. The rarer Calapogon orchids still occur at Brooker Creek Preserve and other undisturbed areas outside of Pinellas County. These are all terrestrial orchids. The small-flowered green fly orchid can be a common site on large trees in areas such as on the Hillsborough River, while the Tampa butterfly orchid, Encyclia tampensis, is found in large swamps and over large river systems. To distinguish them, look at the base of the leaves. If there is a "bulb," it is a butterfly orchid. If it looks like a mat of leaves without a fattened base, it is a green fly.