RAFFLESIA

Rafflesia is a genus of parasitic flowering plants. It contains approximately 28 species (including four incompletely characterized species as recognized by Willem Meijer in 1997), all found in southeastern Asia, on the Malay Peninsula, Borneo, Sumatra, Thailand and the Philippines.

Rafflesia was found 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 was discovered even earlier by Louis Deschamps in Java between 1791 and 1794, but his notes and illustrations, seized by the British in 1803, were not available to western science until 1861.[citation needed]

The plant has no stems, leaves or true roots. It is an holoparasite of vines in the genus Tetrastigma (Vitaceae), spreading its absorptive organ, the haustorium, inside the tissue of the vine. The only part of the plant that can be seen outside the host vine is the five-petaled flower. In some species, such as Rafflesia arnoldii, the flower may be over 100 centimetres (39 in) in diameter, and weigh up to 10 kilograms (22 lb). Even the smallest species, R. baletei, has 12 cm diameter flowers. The flowers look and smell like rotten body, hence its local names which translate to "corpse flower" or "meat flower" (see below). The foul odor attracts insects such as flies, which transport pollen from male to female flowers. Most species have separate male and female flowers, but a few have bisexual flowers. Little is known about seed dispersal. However, tree shrews and other forest mammals eat the fruits and disperse the seeds. Rafflesia is the official state flower of Indonesia, the Sabah state in Malaysia, and of the Surat Thani Province, Thailand.

The name "corpse flower" applied to Rafflesia can be confusing because this common name also refers to the titan arum (Amorphophallus titanum) of the family Araceae. Moreover, because Amorphophallus has the world's largest unbranched inflorescence, it is sometimes mistakenly credited as having the world's largest flower. Both Rafflesia and Amorphophallus are flowering plants, but they are only distantly related. Rafflesia arnoldii has the largest "single" flower of any flowering plant, at least in terms of weight. A. titanum has the largest "unbranched" inflorescence, while the talipot palm (Corypha umbraculifera) forms the largest "branched" inflorescence, containing thousands of flowers; the talipot is monocarpic, meaning the individual plants die after flowering.

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.


When Rafflesia is ready to reproduce, a tiny bud forms on the outside of the root or stem and develops over a period of a year. The cabbage like head that develops, eventually opens to reveal the flower. The stigma or stamen are attached to a spiked disk inside the flower. A foul smell of rotting meat attracts flies and beetles to pollinate. To pollinate successfully, the flies and/or beetles must visit both the male and female plants, in that order. The fruit produced are round lots filled with smooth flesh including many thousands of hard coated seeds that are eaten and spread by tree shrews.

    The flower with the world's largest bloom is the Rafflesia arnoldii. This rare flower is found in the rainforests of Indonesia. It can grow to be 3 feet across and weigh up to 15 pounds! It is a parasitic plant, with no visible leaves, roots, or stem. It attaches itself to a host plant to obtain water and nutrients. When in bloom, the Rafflesia emits a repulsive odor, similar to that of rotting meat. This odor attracts insects that pollinate the plant.

Another enormous flower found in Indonesia is the Amorphophallus titanum, or Titan arum. It is also known as the "corpse flower" for its unpleasant odor. Like the Rafflesia, the Titan emits the smell of rotting flesh to attract pollinators. Technically, the Titan arum is not a single flower. It is a cluster of many tiny flowers, called an inflorescence. The Titan arum has the largest unbranched inflorescence of all flowering plants. The plant can reach heights of 7 to 12 feet and weigh as much as 170 pounds!

Conservation status:

How many of these plants still survive is unknown, but as the remaining primary forests of Borneo and Sumatra disappear, it can be assumed that their numbers are dwindling. Many are known to be nearing extinction[citation needed]. Some environmentalists are developing ways to recreate the species' environment in an effort to stimulate their recovery. This has proved unsuccessful so far. Steps are also being taken to conserve the forests of Sumatra and Borneo. To help counter the over-collection of this rare plant, residents that have Rafflesia on their private property are encouraged to save the flowers and charge a small fee to see them.