There are many orchids that are colloquially referred to as "ghost orchids", but one particular species has become famed over and above all the others due to its coverage in the Susan Orlean book, The Orchid Thief, and the subsequent film treatment by scriptwriter Charlie Kaufman and director Spike Jonze - Adaptation. This flower is indeed beautiful, but the passion it arouses in collectors and growers - and the lengths they will go to obtain one - is equally as fascinating.
Sorta boring, but nonetheless important botanical stuff
This particular ghost orchid is known as Polyrrhiza lindenii ¹, and it is a most peculiar plant indeed - even for an orchid. For a start, it is totally leafless. Well almost - when the plant is just a seedling it sports two tiny vestigial leaves, only 5 -10 mm long, but these are shed as the plant matures. Unless the plant is blooming, which occurs only in the summer months, all that will alert you to its presence is a tangle of green to silvery roots. Indeed, the primary genus name - Polyrrhiza means "many roots". Ghost orchids conduct photosynthesis entirely in the roots where the chlorophyll is located after the initial vestigial leaves are shed. Furthermore, it is an epiphyte, which means it grows on other trees - but purely as a means of support as epiphytes take no nutrients from their hosts. In the wild, these hosts will most often be the bald cypress, pond apple and pop ash trees. This ghost orchid has a complex mycorrhizal symbiosis, which means it lives in a mutually beneficial relationship with a naturally occurring fungus. In the absence of this fungus the plant suffers and will most likely die, not because it feeds the orchid roots directly, but because it assists in the uptake of nutrients from rainfall and the air.
The plant is native to Cuba and the West Indies - in particular the Bahamas, but it is also found throughout Southern Florida in State Reserves such as the Everglades National Park, Big Cypress National Preserve and the Fakahatchee Strand State Preserve. How the ghost orchid came to reside in Florida is a matter of some little contention, but there are two strong theories. Orchid seeds are tiny, microscopically tiny. If you have ever cooked with a vanilla bean, which is the seedpod of the Vanilla planiflora orchid, you will have a good idea of the scale involved. Dishes cooked with vanilla beans leave countless tiny black flecks behind, each black fleck being a single orchid seed. An orchid pod contains millions of tiny, lightweight seeds and the ghost orchid is no exception. One theory has it that migratory birds ate, carried, then deposited the seeds with their guano. A more violent and ultimately more romantic theory is this. Hurricane winds are believed responsible, leaving delicate beauty as the bounty of their destructive wake.
Orchids are pollinated in a multitude of ways. Insects are the vectors responsible for many species of orchid, and in some cases only a single insect is responsible. This is thought to be the case with the ghost orchid. Without the insect in question being caught in flagrante delicto and in situ, which has never occurred with the ghost orchid, there is only one avenue left to determine the culprit - anatomy. By studying the anatomy of the flower structure and the anatomy of an insect, it is possible to identify the pollinator in question. Charles Darwin once famously did this with a particular species of orchid, Angraecum sesquipadale, a stunningly white Madagascan bloom, which has a nectar spur with a ridiculous 300 mm length. He hypothesized an insect with a matching gargantuan proboscis as the vector - the problem was that no insect had ever been found with such John Holmesesque proportions, almost double what had previously been observed. The scientific community thought him once again mad. It was not until after his death that the stunningly endowed Hawk moth (Xanthopan morgani predicta - notice the specific epithet) was found, and Darwin was vindicated - again. In the case of the ghost orchid, the spur is about 5 inches long, with the sugar-dense nectar located right at the bottom. It takes an insect with a pretty big schnozz to reap that bounty. Enter the giant sphinx moth, which is found in the American tropics, Cuba and Southern Florida - and you guessed it, this moth has a 5 - 6 inch proboscis.
Much more interesting and descriptive stuff
So why the fuss over a tangle of roots that grow on a handful of tropical trees? It comes down to one simple and stunning aspect of the plant - the flower. Ghost orchid flowers are breathtakingly beautiful. Orchid flowers are divided into 6 visible sections, 3 sepals and 3 petals, however it is the third petal where most of the action takes place. It is highly modified, and unfailingly different from the remaining 2 petals, so much so that it has its own name - the labellum. In the case of the ghost orchid, the sepals and 2 petals are straight and gently tapering - about 2 inches long. The labellum however, is comparatively enormous. It branches out in a triangular shape, roughly 1 inch wide at the base, and 1 inch high. Protruding from each side of the base of the triangle are two thin, spiraling attachments. They look like some kind of ivory-hued Fu Manchu mustache. The entire flower can grow up to 5 inches long and 3 1/2 inches wide. It is a ghostly, beguiling shade of white - providing the plant with its most common name. The twisting extensions to the labellum also resemble the legs of a leaping frog - leading to another of its common names, the frog orchid.
There are other reasons for the plant's popularity, and to delve into these, you will need to understand a little about the psyche of an obsessed orchid grower. Orchid addicts are a funny bunch - they collect, read, grow, discuss, travel, tend, and spend to an obsessive level. On occasion, they also covet what they perhaps shouldn't - plants that are expensive, plants that really shouldn't be grown in their local climatic conditions, plants that are near enough impossible to grow successfully in captivity, plants stinking with the cachet of exotica. The ghost orchid meets these requirements in spades. First off, check your bank balance. A small ghost orchid seedling will set you back in the order of US $60.00, and this is most definitely entry level only. Prices leap at an exponential rate with more mature plants and further still with respected or show awarded cultivars.
Secondly, this plant is on the endangered list, which only serves to increase it's perceived rarity, and after which status and peer approval naturally flow. Finally, ghost orchids are notoriously difficult to cultivate successfully in captivity, and when I say successfully, I mean to flower, which is the capitulation of the plant's life cycle. To the normal gardener, something so difficult to nurture would normally be cause for alarm - but not for some obsessives, who see it plainly as a challenge. Numerous web forums have been dedicated in recent years to the successful culture of this botanical wonder, and most posters report (shy) failure. So just how hard are they to grow? A peek at the ghost orchid's natural cultural conditions should illustrate the point nicely. It lives in the tropics, so you will need to get the temperature up fairly high. The conditions in the Fakahatchee Strand in July, or mid flowering season are something like this; the temperature ranges from 32° to 35° C (90° to 95° F), the humidity hovers between a stifling 90% and 98%. It rains for at least a few hours each and every afternoon, but the orchid is never rained on directly, it receives cover from the tree it grows on and any water taken in trickles running down the trunk. It grows in constant shade - only ever seeing filtered sunlight. In the early morning dark there is no airflow, but around 9:00 AM when the sun heats the ambient moisture up, a gentle breeze starts. This breeze further increases at around 2:00 PM when the rains begin to fall, then dies down again in the middle of the night. Oh - and don't forget the fungus, essential for the mycorrhizal relationship key to the ghost orchid's survival. Trying to emulate these conditions in a temperate environment could well drive you insane.
A further factor spreading the popularity of the plant was the Susan Orlean book, The Orchid Thief, as well as the subsequent film starring Nicolas Cage and Meryl Streep. It details the story of John Laroche, an archetypal orchid obsessive who enlisted the aid of local Seminoles to collect these endangered orchids from the wild. It was his get rich quick plan. Using mericlone propagation, a complicated process of cloning the orchid using tissue samples, he was going to market ghost orchids to the world, and by enlisting the Seminole locals, he was slyly attempting to circumvent any laws by exploiting the native title they possessed over the land. His ploy was doomed from the outset - on both legal and biological counts, but it does make for an intriguing story of obsession.
Sadly, over the last 50 years, poaching of this wonderful ghost orchid, along with draining of swampland has seen numbers decline in Florida at an alarming rate. It is said that you could find ghost orchids in Florida State Reserves without too much trouble in the 1950s - but this is certainly not the case today. The chances of finding a blooming specimen are quite slim indeed - reinforced by the fact I could find only one picture of a wild bloom on the great big wide internet. In an attempt to reverse this trend, ghost orchids are listed as endangered on the Florida State list of threatened and endangered plants.
All this fuss for a flower - but oh, what a flower.
¹ (syn. Polyradicion lindenii, Dendrophylax lindenii, Aeranthes lindenii, Angraecum lindenii)
Sources of reference