Rafflesia arnoldii is a member of the genus
RafflesiaRafflesia is a genus of parasitic flowering plants. It was discovered in the Indonesian rain forest by an Indonesian guide working for Dr. Joseph Arnold in 1818, and named after Sir Thomas Stamford Raffles, the leader of the expedition...
. It is noted for producing the largest individual flower on earth. It occurs only in the
rainforestRainforests are forests characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1750–2000 mm . The monsoon trough, alternately known as the intertropical convergence zone, plays a significant role in creating Earth's tropical rain forests.From 40 to 75%...
s of
SumatraSumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world .-Etymology:Sumatra was known in ancient times by the Sanskrit...
and
BorneoBorneo is the third largest island in the world and is located at the centre of Maritime Southeast Asia. Administratively, this island is divided among Indonesia , Malaysia and Brunei . Indonesians refer to the island as Kalimantan...
in the
Malay ArchipelagoThe Malay Archipelago and Maritime Southeast Asia are names given to the archipelago located between mainland Southeastern Asia and Australia. Located between the Indian and Pacific Oceans, the group of 20,000 islands is the world's largest archipelago by area...
. Although there are some plants with larger flowering organs like the
Titan ArumThe titan arum or Amorphophallus titanum is a flowering plant with the largest unbranched inflorescence in the world...
and
Talipot palmCorypha umbraculifera is a species of palm, native to southern India and Sri Lanka.It is one of the largest palms in the world; individual specimens have reached heights of up to 25 m, with stems up to 1.3 m in diameter...
, those are technically clusters of many flowers.
Several species of
Rafflesia grow in the jungles of southeast Asia, including the Philippines.
Rafflesia arnoldii is a member of the genus
RafflesiaRafflesia is a genus of parasitic flowering plants. It was discovered in the Indonesian rain forest by an Indonesian guide working for Dr. Joseph Arnold in 1818, and named after Sir Thomas Stamford Raffles, the leader of the expedition...
. It is noted for producing the largest individual flower on earth. It occurs only in the
rainforestRainforests are forests characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1750–2000 mm . The monsoon trough, alternately known as the intertropical convergence zone, plays a significant role in creating Earth's tropical rain forests.From 40 to 75%...
s of
SumatraSumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world .-Etymology:Sumatra was known in ancient times by the Sanskrit...
and
BorneoBorneo is the third largest island in the world and is located at the centre of Maritime Southeast Asia. Administratively, this island is divided among Indonesia , Malaysia and Brunei . Indonesians refer to the island as Kalimantan...
in the
Malay ArchipelagoThe Malay Archipelago and Maritime Southeast Asia are names given to the archipelago located between mainland Southeastern Asia and Australia. Located between the Indian and Pacific Oceans, the group of 20,000 islands is the world's largest archipelago by area...
. Although there are some plants with larger flowering organs like the
Titan ArumThe titan arum or Amorphophallus titanum is a flowering plant with the largest unbranched inflorescence in the world...
and
Talipot palmCorypha umbraculifera is a species of palm, native to southern India and Sri Lanka.It is one of the largest palms in the world; individual specimens have reached heights of up to 25 m, with stems up to 1.3 m in diameter...
, those are technically clusters of many flowers.
Description
Several species of
Rafflesia grow in the jungles of southeast Asia, including the Philippines. Many of them are threatened or endangered. The flower of
Rafflesia arnoldii is the largest which attains a diameter of nearly one meter (3 ft) and can weigh up to 11
kilogramThe kilogram is the base unit of mass in the International System of Units .[The spelling kilogram is the modern spelling used by the International Bureau of Weights and Measures , the U.S...]
s (24
lbThe pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement...
).
It lives as a parasite on the
TetrastigmaTetrastigma is a genus of plants in the grape family, Vitaceae. The plants are vines that climb with tendrils and have palmately compound leaves. The species are found in subtropical and tropical regions of Asia, Malesia, and Australia, where they grow in primary undisturbed rainforest...
vine, which grows only in primary (undisturbed) rainforests.
Rafflesia lacks any observable
leavesIn botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. There is continued debate about whether the flatness of leaves evolved to expose the chloroplasts to more light or to increase the absorption of carbon dioxide. In...
,
stemsA stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , cones or other stems etc. The internodes act as spaces that distance one node from another...
or even
rootIn vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s, yet is still considered a vascular plant. Similar to fungi, individuals grow as thread-like strands of tissue completely embedded within and in intimate contact with surrounding
host cellsIn biology, a host is an organism that harbors a parasite , or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
from which nutrients and
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
are obtained. Perhaps the only part of
Rafflesia that is identifiable as distinctly plant-like are the flowers; although, even these are unusual since they attain massive proportions, have a reddish-brown coloration and stink of rotting flesh, which is why it was nicknamed the "corpse flower". This scent attracts insects such as flies which then pollinate the rare plant. It is not to be confused with the
Titan ArumThe titan arum or Amorphophallus titanum is a flowering plant with the largest unbranched inflorescence in the world...
,
Amorphophallus titanum, which is also commonly referred to as the "corpse flower".
Reproduction
Rafflesia arnoldii is rare and fairly hard to locate. It is especially difficult to locate the flower in forests as the buds take many months to develop and the flower lasts for just a few days. The flowers are unisexual and thus proximity of male and female flowers is vital for successful pollination. These factors make successful pollination a rare event.
Survival
How many of these plants still survive is unknown, but as the remaining primary forests of Borneo and Sumatra disappear, it can only be assumed that their numbers are dwindling. Many are known to be nearing
extinctionIn biology and ecology, extinction is the end of an organism or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species...
. Some
environmentalistAn environmentalist supports any goal of the environmental movement, an information-based perspective on appropriate use of technology to prevent adverse effects on the environment...
s are thinking of a way to recreate the species' environment, in an effort to stimulate a recovery in the population of this endangered
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
. This has proved unsuccessful so far, but the efforts have continued. Steps are also being taken to conserve the forests of Sumatra and Borneo.
External links
- http://homepages.wmich.edu/~tbarkman/rafflesia/Rafflesia.html
- http://www2.canada.com/vancouversun/news/story.html?id=1055e283-e191-4c9d-a3c9-c6454ce38970