Deep beneath the Florida peninsula lie rocks matching geologic formations in West Africa. These rocks are remnants from a time some 280 million years ago when the great southern land mass of Gondwana smashed into the northern land mass of Laurasia, forming the supercontinent Pangea. When Pangea split apart some 70 million years later, a little piece of what became Africa remained with the land mass that became North America, forming the basement strata for what is known today as Florida.
Geologists Douglas L. Smith and Kenneth M. Lord put it in more precise scientific language in their chapter in The Geology of Florida (1997): "It is reasonably well established that the Florida Platform block was originally a part of the West African continental margin near Senegal, and was only rifted from that margin during the Triassic breakup of Pangea. . Specific [geologic] units in West Africa can be correlated with their apparent counterparts underlying the Florida Platform."
In more recent geological times, orchids have migrated to Florida from Africa, continuing the unexpected natural connection between these two areas of the globe now so distantly divided.
Today, Florida shares four species of orchids directly with Africa. Additionally, Florida's three leafless orchid species, including the legendary ghost orchid, are among a handful of New World outliers from a group of orchids that evolved in Africa. A few other species of Florida's wild orchids show affinities with African orchids as well.
It seems unlikely that most of these species made the leap directly from Africa to Florida. Subtropical South Florida - where most of these African-related orchids now occur - as we know it today is just too new for that to have happened because the area from Lake Okeechobee southward began to emerge from its latest inundation by the sea only some 80,000 years ago.
Rather, these orchids of African affinity probably hopscotched northward from South America - where the distance between the eastern hump of Brazil and the western hump of Africa is only some 1,800 miles - to Florida via Central America or, more likely, the islands of the Caribbean Sea.
But you may ask how they got from Africa to South America in the first place. Nobody knows for sure. However, in an article on the African-evolved Oeceoclades maculata in the September 1988 American Orchid Society Bulletin , William Louis Stern discusses one theory. He says some scientists believe that 54 million years ago, when many currently recognized plant families were already in existence, Africa and South America lay only 500 miles apart and numerous volcanic islands bridged that gap. "It is conjectured,"Stern writes, "that this proximity and the occurrence of the intervening islands were conducive to the migration of plants (and animals) between Africa and South America." Whether the orchid exchange took place at that time or later remains scientific guesswork, but this represents one possibility.
Because of the wind-borne distribution of the dustlike seeds of most orchids, it is possible that the arrival of African orchids in the New World could have taken place in more recent geologic times over greater distances. However, William W. Sanford, in The Orchids: Scientific Studies (1974), writes that many orchidologists dismiss the idea of such long-distance dispersal of orchid seeds.
But there are two meteorological phenomena the make the theory of such wide dispersal plausible, and both involve wind.
From June through November, windy waves of moisture-laden clouds blow from the tropical West Africa over the Atlantic Ocean and, under the right environmental conditions, form into tropical cyclones called hurricanes. These can cross the Atlantic with considerable speed until they make landfall in the Western Hemisphere. Admittedly, though, these storms blow to the islands of the Caribbean or the mainland of Central America or North America and rarely touch the continent of South America.
In addition, from late June through August, dust from northern Africa is blown on the fast-moving currents of the trade winds to South Florida, creating an unusual haze that colors the sky a reddish hue, always prompting stories in the local newspapers.
If these winds, whether hurricane or dust cloud, contain orchid seeds, it is possible they could survive the quick, cool ride across the Atlantic from Africa.
Of course, that's just part of the cycle. To survive in this new land, the seeds would have to fall on a suitable surface and be infected at the right moment by an acceptable mycorrhizal fungus to complete their growth into a mature orchid plant. Then, to exist as anything but a solitary waif, this mature orchid would have to have some proximity to other plants with which it is genetically compatible. This all must occur at flowering time, and there must be an appropriate agent - usually an insect of correct proportions and inclination - to transfer pollen from one plant to another for the cross-pollination to occur that will help perpetuate the species.
The odds of all these events occurring in a fortuitous sequence are astronomical. But, considering the vastness of geologic time (versus man's limited time frame) and the fact that orchid seeds are produced by the millions, it seems logical to assume that such an event could have occurred occasionally, accounting for these African outliers in the New World.
Self-fertilizing forms of a species would have a greater advantage in establishing viable colonies in a new home, and there are several well-known examples in Florida, including such orchids as Encyclia cochleata, Encyclia boothiana, Epidendrum nocturnum and Bletia purpurea. However, none of these species is of African ancestry.
Besides possibly bringing orchids from Africa to the New World, hurricanes also could account for the dispersal of African-related orchids from tropical America into subtropical South Florida because they often follow paths through the Antilles or from the Central American coast where these orchids might occur before the storms make landfall in Florida.
A prime example: In mid-October 1999, a minimal hurricane named Irene formed suddenly in the Caribbean and, in a matter of a few days, blew over the western end of Cuba, crossed the Florida Straits in just hours and made its way from Key West, across Florida Bay and Cape Sable, then up the middle of the Everglades, with its winds reaching outward all along the southeastern coast of peninsular Florida. Any orchid seeds dehiscing in Cuba at that time easily could have been picked up in the swirling winds, brought to Florida in viable condition, and deposited in likely habitats. This scenario must have played out again and again over many millennia, no doubt accounting for the tropical orchids Florida shares with Cuba and other lands to the south.
Some authors also have theorized that animals, especially birds, might be occasional agents for the dispersal of orchid seeds, perhaps carrying the dustlike particles on their feathers or feet.
Carlyle A. Luer, MD, in The Native Orchids of the United States and Canada (1975), discusses just such a situation in his comments on the Hawaiian terrestrial Platanthera holochila. Luer considers this orchid of mountaintop bogs on the older Hawaiian Islands to be indistinguishable from Platanthera hyperborea var. viridiflora from the Aleutian Islands and the southern coast of Alaska far to the north. Opining about his theory of how this species crossed the ocean, he writes, "Seeds should not find transportation to the [Hawaiian] islands wanting, since the Pacific golden plover migrates annually between the cold bogs of Alaska and these high cool bogs of Hawaii. As evidence, a sun-dew (Drosera anglica), also common in the Alaskan bogs, probably also spanned the great distance in mud on the feet of birds."
Humans, too, have been considered a means of dispersal for some tropical orchids found in the wild in South Florida. Some of these have African origins and will be discussed later.
For all the theorizing about how these orchids of African affinity got to South Florida, the simple fact is that they are here. Part I of this article will look at the four orchids with direct connections to Africa. Parts II and III will discuss those species that have African ancestors - or at least relatives - there.
Of the four orchid species Florida shares directly with Africa, two are now considered Pantropical. The other two are shared only between Africa and the Western Hemisphere.
Polystachya concreta (Jacquin) Garay and Sweet
Africa is the center of distribution for the genus Polystachya, with about 150 species occurring there, according to Joyce Stewart and Esmé Hennessy in Orchids of Africa: A Select Review (1981). (Oddly, Robert L. Dressler, in Phylogeny and Classification of the Orchid Family , lists that number for the whole genus worldwide.)
A few polystachyas, though, managed to make it to the New World, where taxonomist Eric A. Christenson, PhD, estimates there are about six to eight species. Two of these (Polystachya concreta and Polystachya foliosa) are widespread in the American tropics, while the others are "more or less narrow endemics," Christenson says (personal communication). All of the New World polystachyas, he points out, are superficially similar and have greenish-yellow flowers. Because of this similarity, it might be theorized that the New World polystachyas evolved from a single ancestor species that blew in from Africa, perhaps even Polystachya concreta itself.
Polystachya concreta is a fairly common epiphyte in the hammocks and swamps of subtropical South Florida, where the peak of the bloom season seems to be in the autumn, although plants flower sporadically in the winter and summer as well.
Besides its currently accepted botanical name, over the past century this species has been known in Florida as Polystachya flavescens (Luer, 1972), Polystachya extinctoria (Long and Lakela, 1971), Polystachya luteola (Correll, 1950) and Polystachya minuta (Small, 1933). In his The Native Orchids of Florida (1972), Carlyle Luer, MD, lists 16 synonyms for this orchid. The widespread distribution accounts for the high number of names.
Besides its huge range in the Western Hemisphere, which includes much of tropical South America, Central America, southern Mexico and the islands of the West Indies, Pol. concreta is found throughout tropical Africa and Madagascar, then skips across the Indian Ocean to occur in southern India and Sri Lanka on into Malaysia, Indonesia and the Philippines, making it truly one of the most pantropical of orchids.
It is only natural that an orchid found in so many places would have a plethora of names. As plant explorers discovered the orchid in the various regions where it grows, they sent specimens back to their respective botanists, who then described the species and assigned it a name. With communication among early taxonomists so limited, it is not surprising, then, that they didn't know they were all dealing with the same orchid. Hence, abundance of names for Pol. concreta.
In Florida, this species can grow as robust plants with long inflorescences producing many flowers. But it also can bloom on tiny plants producing few flowers. The larger plants will bear numerous secondary racemes below the terminal one, accounting for the genus name, which comes from two Greek words meaning "many spikes of grain," or just "many spikes."
No matter the size of the plant, the individual greenish-yellow flowers are tiny. They are nonresupinate, bearing the lip at the top of the flower. This lip is covered with hairs, which have a granular appearance vaguely resembling pollen. Attracted by a sweet midday fragrance, a tiny bee crawls upside-down into the flower to gather these hairs, dubbed "pseudopollen," and while scratching around in the flower, picks up or deposits the orchid's pollinia. No matter what the bee uses the pseudopollen for, the lure must be successful because numerous seed capsules are produced without the aid of any self-fertilizing mechanism, according to Gary J. Goss, who studied the pollination of this orchid in Florida and reported on it in a fascinating article published in the November 1977 AOS Bulletin.
The robust plants of Pol. concreta must be a disappointment to people who have collected this species out of bloom (and usually illegally) because the flowers are so small for the size of the vegetative growth. In this respect, this species is different from some of its African relatives, which can produce colorful, showy flowers.
The state of Florida considers Pol. concreta endangered within its borders (Coile, 1998), although it is certainly plentiful in the southern end of the state and elsewhere in tropical America.
Liparis nervosa (Thunberg) Lindley
When Carlyle A. Luer, MD, wrote about this orchid in The Native Orchids of Florida, it was still known as Liparis elata and he showed it ranging from Florida through the Antilles and from southern Mexico, Central America and northwestern South America to the isolated Galapagos Islands. Interestingly, though, the type specimen for John Lindley's 1828 Liparis elata is listed as coming from "Brazil, Rio de Janeiro," but Luer's distribution map shows it growing nowhere near that city on Brazil's Atlantic coast.
Now, however, L. elata is considered synonymous with Liparis nervosa, which is based on a plant from Japan that Carl Peter Thunberg originally described as Ophrys nervosa in 1784.
Leslie A. Garay and Herman R. Sweet, in their treatment of the orchids of the Lesser Antilles (1974) consider L. nervosa Pantropical. Eric A. Christenson, PhD (personal communication) writes, "Although some don't like the idea of Garay's lumping names into one species, I have examined type material of two names, one from New Guinea and one from Tanzania, and find them identical to the Neotropical plants."
Out of the approximately 350 species of Liparis worldwide (Dressler, 1993), the greatest number seems to grow in southern Asia and the adjacent islands of the Pacific. Numbers for Liparis in the New World were impossible to track down, partly because, as with many large groups of orchids, the taxonomy is in a state of flux at the moment. For Africa, though, Stewart and Hennessy (1981) list only about 20 species. One of these is L. nervosa as the species is understood today, so there is another orchid that Florida shares directly with Africa.
In Florida, L. nervosa occurs in two areas. In west central Florida, it has been reported from Hillsborough and Hernando counties, where the species grows terrestrially in dense hardwood forests. Some 250 miles to the south, it occurs in the vast recesses of the Fakahatchee Strand at the western edge of the Big Cypress Swamp. There, it grows primarily in leaf litter on cypress knees and old tree stumps, as well as on decaying logs floating in the water of the swamp. However, even in the Fakahatchee, it has been observed at least once growing terrestrially in the mud of a small tree island at the edge of a swamp. The semi-epiphytic existence of L. nervosa in the Fakahatchee should not be surprising. Elsewhere in the world, other species of Liparis are distinct epiphytes.
Luer illustrates plants of L. nervosa from Hernando County, in the northern population, flowering in July. In the Fakahatchee Strand, the plants generally bloom from late August into September.
It's sad that this orchid hasn't been brought into cultivation successfully, because it is a horticulturally attractive species. The conical pseudobulb produces three to seven wide green leaves with deeply indented parallel veins, no doubt accounting for the species epithet, which probably refers to these distinctive nerves. The inflorescence can grow to more than 2 feet in length. This height accounts for the other species name, elata, which means "high," and sometimes this species is known in Florida by the common name tall liparis.
The unbranched scape can bear 30 or more small, waxy flowers that are green suffused with purple. The look of the flowers immediately identifies them as Liparis for anyone who is at all familiar with the genus.
Liparis nervosa is classed as endangered by the state of Florida (Coile, 1998), and this classification is certainly justified. This is not a common orchid anywhere in the state.
Eulophia alta (Linnaeus) Fawcett and Rendle
As with Polystachya, Africa is the center of distribution for the genus Eulophia. There are 181 species on the African continent proper, according to the latest count (Thomas, 1998). Also, as with Polystachya, Eulophia is a Pantropical genus, with 230 species worldwide.
However, unlike Polystachya, only one species of Eulophia occurs in the New World, as the genus is now understood (Thomas, 1998). And this species, unlike Pol. concreta, is not Pantropical in its distribution. From tropical Africa, where it is widespread eastward from the Great Rift Valley, Eulophia alta has dispersed only westward. But what a successful dispersal that has been.
In South America, this species covers all of the tropical part of the continent except the higher portions of the Andes and the drier regions of the Pacific coast, and it even dips down into the subtropical regions of Paraguay, northern Argentina and southeastern Brazil. It also occurs in southern Mexico, Central America, the Antilles and Florida. In Florida, it grows over a good portion of the peninsula, from the deep subtropical south as far north as Pasco County on the Gulf coast and Flagler County on the Atlantic side of the state. In fact, the range of this species in the Western Hemisphere seems to exceed its range in its native Africa.
Because of its African origin, some people do not want to believe this orchid got to the New World by natural means. Donovan S. Correll notes in Native Orchids of North America North of Mexico (1950): "The occurrence ... of this essentially African genus in the Western Hemisphere is another mystery in the realm of plant distribution. As in the case of a number of anomalous species found in the West Indies and other parts of tropical America, it is thought that some of these plants were introduced into the New World by slaves in the early days of the slave trade, either for their supposed healing powers, for use in voodooistic practices or for food."
Correll doesn't expand on this idea or cite his sources. What he described may have occurred, but somehow it seems unlikely, considering how widely the species has spread in the New World. It seems unlikely it could have reached its present broad distribution in only some 450 years. But in the plant world, you can never say never. Just look at Oeceoclades maculata (discussed below), which seems to have been spreading with breakneck speed through the American tropics.
Eulophia alta is another of those handsome native terrestrial orchids that deserve to be brought into cultivation. It prefers the sunny habitats of open glades and roadsides, where it is readily visible, even when not in bloom. The beautiful yellowish-green pleated leaves resemble a palm seedling, accounting for the species' common name in Florida, wild coco.
From the plant's cormlike pseudobulb, an inflorescence begins to emerge in late summer or early autumn in South Florida. This bloom stem can grow from just a couple of feet tall to more than 6 feet under optimum conditions, and it is this "altitude," or height, to which the species name refers.
The 20 to 60 1 1/2-inch-wide flowers are beautifully arranged along the tip of the inflorescence. The three sepals all point more or less upward, far different from the sepal arrangement in, say, a Cattleya flower.
The lateral petals arch over the lip, forming a tube, perhaps to guide a visiting insect into proper alignment for pollination. The lip is covered with a crest of fingerlike projections, justifying the generic name, Eulophia, which means "well-crested."
The basic flower color is yellowishgreen overlaid with purple. The coloration varies, with some flowers producing sepals in honey tones against the reddish-purple petal-lip combination. Sometimes, the sepals are the same rich reddish-purple shade as the lip, and sometimes they are a dull green. A rare color form with no purple pigment has been seen. It has clear green sepals with a beautiful white lip.
In the United States, Eupha. alta generally blooms from September into January, with the peak coming in the late fall, making this showy species one of the autumn delights of South Florida's wild places.
Earlier lists of species protected by the state of Florida classed Eupha. alta as threatened, but the latest list (Coile, 1998) does not include it. Its removal from the list is justified because this orchid is widespread and relatively common in the state.
Oeceoclades maculata (Lindley) Lindley
Related to Eupha. alta, this orchid is a newcomer to the wilds of Florida, having first shown up in the early 1970s in a hammock along the Atlantic coastal ridge south of Miami, too late to be included in The Native Orchids of Florida, according to Roger Hammer (1981). Since then, though, it has been spreading like wildfire across the southern tip of the peninsula (McCartney, 1983). In the 25 or so years since its discovery in Florida, it has managed to make considerable inroads into five of the seven counties south of Lake Okeechobee.
In fact, this orchid has been so successful in establishing itself in South Florida that it has become a victim of its own excess, earning the distinction of being the only orchid classified as an exotic pest plant by the State of Florida. This unfair designation has led to its persecution by public land managers, who, based on that quite incorrect classification, are ripping it out of the ground and throwing it away wherever they find it - much to the chagrin of orchid lovers.
One of the problems with the designation is that there is no firm evidence that this orchid was introduced into South Florida by humans. The botanical gurus of Florida's Exotic Pest Plant Council who drew up this list consider that all natural migration of plants stopped in 1513, when Juan Ponce de Leon's expedition is credited with discovering Florida for the Europeans. Any plant that found its way here on its own since then is not considered by these people as a native and is, therefore, anathema.
The other problem with the designation is the word "pest." Florida has many, many naturalized exotic plants that are, indeed, pests: melaleuca, Brazilian pepper, Australian pine, old world climbing fern and on and on. These species truly endanger our native flora and fauna because of their rampant growth. But there is no evidence that O. maculata is endangering any other plant or animal species, even though it sometimes grows in dense clumps on the floor of the native tropical hardwood hammock habitats it seems to prefer.
Oeceoclades is another African-centered genus, with about a dozen of the approximately 30 species occurring on the continent and most of the rest growing on the island of Madagascar off Africa's east coast (Stewart, 1988). Oeceoclades maculata grows across tropical Africa, and, like Eupha. alta, is the only member of its genus to reach the New World, where it occurs throughout much of South America, the islands of the West Indies, and now Florida.
This orchid has been known in the Western Hemisphere since at least 1829, when it was reported from Brazil, as Stem recounts in his masterful article on O. maculata in the September 1988 AOS Bulletin. And even though this is an orchid of African origin, Stem points out that John Lindley's initial 1821 scientific description of the species apparently was based on a plant collected in South America.
What has driven the explosive dispersal of this orchid in the New World has been a subject of much speculation. It appears to be largely self-fertilizing, producing seeds by the millions with the aid of rain striking the flowers and knocking the pollinia loose so they can contact their own stigmatic surface as the stipe dries and curves backward (González-Diáz and Ackerman, 1988). But the wind alone may not be the only force spreading the seeds of this orchid around. The movement of this species from South America seems to have generally been northward along the arch of the Antilles, the same route suspected to have brought the African cattle egret (Bubulcus ibis) to North America. Possibly it was a dispersal agent for this species. But cattle egrets seem to prefer open areas, whereas O. maculata is generally a forest dweller. Maybe the orchid just island-hopped on its own to Florida by wind-borne seed dispersal. But no matter how it got here, it is here to stay, permanently a part of our South Florida orchid flora, despite the worst efforts of misguided natural-area managers to eradicate it.
The plant is quite pretty, with large, succulent leaves of dark green mottled with white, in the manner of the mottled-leaved species of Paphiopedilum or Phalaenopsis. The species name, maculata, refers to the spots creating this mottling. The orchid also could be mistaken for some ornamental snake plant in the liliaceous genus Sansevieria. It grows in clumps in the leaf litter of the forest floor, its thick, spongy white roots running through the humus but never digging very deeply into the soil.
In late August and September continuing into early winter, a bloom stem emerges and produces pretty little pinkish-tan flowers arranged around the tip. The lip is white with a beautiful pinkish-magenta spot on each side of the mid lobe. The center of the lip is ornamented with a large butterfly-like crest, and the back of the lip forms into a rounded spur that politely could be described as "scrotiform."
Oeceoclades maculata is an orchid worthy of cultivation, if only for its beautifully spotted leaves. And plants should be easy to obtain. Just look on the trash piles where it has been thrown out by the land managers.
Note: In the March and April issues of Orchids, Parts II and III of this article will take a look at the Florida orchids with close African ancestors, including the leafless orchids, and some that are more distantly related.
Coile, Nancy C. 1998. Notes on Florida's Endangered and Threatened Plants. Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Bureau of Entomology, Nematology and Plant Pathology - Botany Section, Contribution No. 38, 2nd edition, Gainesville.
Correll, Donovan Stewart. 1950. Native Orchids of North America North of Mexico. Chronica Botanica Co., Waltham.
Dressler, Robert L. 1993. Phylogeny and Classification of the Orchid Family. Dioscorides Press, Portland.
Garay, Leslie A., and Herman R. Sweet. 1974. Orchidaceae in Flora of the Lesser Antilles [Richard A. Howard, Ed.], Arnold Arboretum, Harvard University, Jamaica Plain.
González-Diaz, Nancy, and James D. Ackerman. 1988. Pollination, Fruit Set, and Seed Production in the Orchid, Oeceoclades maculata, Lindleyana 3(3):150-155.
Goss, Gary J. 1977. The Reproductive Biology of the Epiphytic Orchids of Florida 6. Polystachya flavescens (Lindley) J.J. Smith, Amer. Orchid Soc. Bull. 46(11 ):990-994.
Hammer, Roger L. 1981. Finding New Orchids: A Contribution to the Orchidaceae of Florida, Fairchild Tropical Garden Bulletin 36(3):16-18.
Long, Robert W, and Olga Lakela. 1971. A Flora of Tropical Florida. University of Miami Press, Coral Gables.
Luer, Carlyle A. 1972. The Native Orchids of Florida. The New York Botanical Garden, Bronx.
____. 1975. The Native Orchids of the United States and Canada Excluding Florida. The New York Botanical Garden, Bronx.
McCartney, Chuck. 1983. Population Explosion, The Florida Orchidist 26:124-129.
Sanford, William W 1974. The Ecology of Orchids, Pages 1-100 In The Orchids: Scientific Studies [Carl. L. Withner, editor], John Wiley and Sons, New York.
Small, John Kunkel. 1933. Manual of the Southeastern Flora. Published by the author, New York.
Smith, Douglas L., and Kenneth M. Lord. 1997. Tectonic Evolution and Geophysics of the Florida Basement, Pages 13-26 In The Geology of Florida [Anthony F. Randazzo and Douglas S. Jones, editors], University Press of Florida, Gainesville.
Stern, William Louis. 1988. The Long-Distance Dispersal of Oeceoclades maculata. Amer. Orchid Soc. Bull. 57(9):960-971.
Stewart, Joyce. 1988. A Brief Overview of the Genus Oeceoclades. Amer. Orchid Soc. Bull. 57(9):972-975.
____, and Esmé F. Hennessy. 1981. Orchids of Africa: A Select Review. Houghton Mifflin Co., Boston.
Thomas, Sarah A. 1998. A Preliminary Check list of the Genus Eulophia. Lindleyana 13(3):170-202.
Chuck McCartney, a former assistant editor (1984 to 1988) and editor (1988 to 1989) of AOS Bulletin, is an avid student of Florida' s native orchid flora. He currently works for The Miami Herald - 2546 Scott St., Hollywood, FL 33020-2357.