The Amazing Life of The Western Underground Orchid
Rhizanthella gardneri, also known as Western Underground Orchid, was discovered in the spring of 1928 in the Wheatbelt region of Western Australia. Its discovery in 1928 caused such an excitement among orchid lovers that a wax model had to be toured around Great Britain. This white leafless plant is made up of a stem which produces a flower head never emerging from he ground. This plant remains completely underground for its entire life. Hence, it not surprising that it is rarely seen and has been discovered by pure luck only. This species is a parasitic plant, but even has a parasitic plant it is strange one. It has no root system. The plant is basically a thickened short rhizome, an underground stem, and depends solely on a peculiar threesome association. Not being able to obtain the sun's energy through photosynthesis as it is leafless, instead it feeds on the broom honeymyrtle (Melaleuca uncinata), a shrub. However, its parasitic habit is not direct to the main host as the Rhizanthella gardneri first associates to a fungus, Thanatephorus gardneri. This fungus is an endophyte of Rhizanthella gardneri. That is, the fungus lives within the underground orchid plant body forming endomycorrhizas and at the same time also forms ectomycorrhizas with the broom honeymyrtle, thus serving as an intermediary between the two plant species. Due to this peculiar association, this particular underground orchid is a called a myco-heterotroph relying totally on the broom honeymyrtle and on the fungus Thanatephorus gardneri for its nutrients and carbon dioxide supply. Having received these from the fungus the plant is then able to convert the water, nutrients and carbon dioxide into the energy needed for growth and maintenance. In reality, the western undergound orchid parisitizes the fungus which then parasitizes the broom honeymyrtle, although at a mutualistic level in this last case. So we have a parasite parasitizing another parasite. This type of association is not so uncommon in the plant kingdom and it is considered a kind of a cheating relationship, as the fungus seems to gain nothing from the orchid, unlike what happens with the broom honeymyrtle. The orchid is thus the cheater, or the villain in this "love triangle". At the beginning of the rain season in autumn, the plant blooms producing a flower structure similar to a tulip. This flower head measures 2.5 to 3 cm and never emerges above ground but simple revolves the soil above it as it grows. The cracks thus opened are sufficient for its tenuous scent to be released and spread nearby attracting flies and other small insects. Strangely, it is the first plant and the only known case of a plant that uses termites as pollinator agents. It is surprising that these tropical insects, one of the most abundant and world wide spread are not used as pollinators more often. However, as fungus, termites avoid light and live underground. Thus, the only flower that could attract them would have to exist also underground. That is precisely what this peculiar orchid does. The flower head, technically an inflorescence, contains 8 to 90 small dark maroon flowers. Rhizanthella gardneri reproduces both vegetatively, by which it can produce three daughter plants, as well as sexually. In the latter case the pollinated flower will then take up to six months to mature. The seeds are thought to be dispersed by marsupials that eat the fruit. But substantial findings are hard to come by as very few specimens have been observed in the wild and only about 300 specimens have been collected to date. This unusual and critically endangered orchid is a particularly challenging species to find. The flowers of the other two species of underground orchids Lamington's Underground Orchid, Rhizanthella omissa, and Eastern Underground Orchid, Rhizanthella slateri, break the surface beneath the leaf litter, to allow pollination by flies or insects. These underground orchids live all in Australia and share the same features and lifestyle as they are all myco-heterotrophs.
More about Plant-Animal Interactions:
- Orchids: A History of Sex, Drugs & Lies
Orchids are probably the most popular flowering plant species. They are also the most evolved from all plants. They managed to spread successfully across the world by developing the most complicated relationships with its pollinators. Some of them ha - The Irresistible Powers of the Corpse plant, Helicodiceros muscivorus
In Mediterranean islands of Sardinia, Corsica and the Balearic islands grows the corpse plant, Helicodiceros muscivorus. If found an unusual yet efficient and smelly way of sucessivly atract blowflies as its main polinators. - The Bullhorn Acacia, Acacia cornigera, and Its Fearl...
Bullhorn Acacia, Acacia cornigera, native of Central America is best known for its symbiotic relationship with a species of ant that lives in it the hollowed-out tree thorns. The ants are famous for defending the tree fearlessly against ravaging inse - The Admirable and Forget-me-not Nepenthes Plants
Apart from being very popular house plants, nepenthes or pitcher plants, as they are more popularly known, have one of most ingenious and effective way of luring and catching their mineral supply - insects. They are evolved flowering plants native fr - The Aerial Life of the Ant Plants Hydnophytum and My...
This group of plants, the ant plants, from the genera Hydnophytum and Myrmecodia, found an efficient way of living and surviving under adverse conditions. The reason for that success lies on the unusual relation that these plants established with the
Southwestern Australi: Home of Western Underground Orchid
More about Parasitic Plants
- The Ancient World of the Colourful and Enduring Lich...
Lichens are found in all continents and climates with the most diverse colours and shapes. They are composite organisms formed by a fungus and one or several photosynthetic partners that can be unicellular green algae or cyanobacteria. Although unoti - The Double Life of Endophytic Fungi
In past considered an oddity, the symbiotic relationship between certain endophytic fungi and their plant hosts seems now to be most common in many species. - The Matelse Mushroom (Cynomorium coccineum): An Epic History of the Rise and Fall of the Treasure of
The story of the Maltese mushroom, on how it rose to prominece and fade away. The Maltese mushroom is not a funus but a parasitic plant. - The Lying Game of the Elusive Botanical Oddity Rhizanthes
In the dark forests of Southeast Asia lies one of the rarest and very unusual plant. Meet Rhizanthes, an elusive and notorious baby killer, also famous for deceiving its visitors. - The Australian Christmas Tree, Nuytsia floribunda, and Its Ingenious Way of Survival
The Australian Christmas tree, Nuytsia floribunda, native of Southwest Australia, is an extraordinary plant. It is the biggest parasitic plant in the world with an ingenious and efficient way of surving. - Parasitic Plants: The Sideshow of the Botanical World
Parasitic plants are a diverse group of plants that adpated and specialized in obtaining water and nutrients from other plants. They are distributed worldwide and produce some of the more amazing structures in the plant world. They can be a serious m