You are here
Taxonomy
Rafflesia
EOL Text
The dramatic Rafflesia flowers are the largest single flowers in the world; the leathery petals can reach over 90 centimetres across (2). Rafflesia is a parasite that depends completely upon its host; the majority of the plant's tissues exist as thread-like strands entirely within the host's cells (3). These host plants are vines of Tetrastigma spp., and the Rafflesia plant is itself not visible until the reproduction stage when flowers first bud through the woody vine and then open into the magnificent spectacle that is world-renowned today (4). The flowers can take up to 10 months to develop from the first visible bud to the open bloom, which may last no more than a few days (5). Currently 17 species of Rafflesia are recognised and these mainly differ in the morphology of their flowers (4). In general however, the flowers consist of 5 leathery petals that are orange in colour and mottled with cream-coloured warts (2). There is a deep well in the centre of the flower containing a central raised disc raised that supports many vertical spines (2). The sexual organs are located beneath the rim of the disk, and male and female flowers are separate (2).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
The enormous Rafflesia flowers are believed to be pollinated by flies; alighting on the central disk flies crawl underneath it where they come into contact with the sexual organs (2). It has been reported that the flowers have a strong smell of rotting flesh but it is unclear whether this acts to attract flies or is merely a by-product of the decaying petals, which reduce into a black slimy mess after around 4 days (2).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
Species of Rafflesia are known from peninsular Malaysia, Sumatra, Java, southern Thailand, Borneo and southern Philippines (4). The genus as a whole is considered to be rare although information on distribution is lacking due to the difficulties of identifying plants within their host vines (4).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
Rafflesia plants are specialist parasites only found in association with specific species of the host vine Tetrastigma spp. These vines are found in both primary and secondary rainforest (4).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
Rafflesia manillana is classified as Endangered on the 1997 IUCN Red List of Threatened Plants (1). R. keithii and R. pricei are classified as Vulnerable; R. cantleyi, R. kerrii and R. zollingeriana are classified as Rare (1); R. hasseltii is classified as Indeterminate (1).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
Rafflesia are inherently rare as a result of a number of factors of their life cycle; they have a double habitat specialisation, as they can only successfully parasitise particular species and these species in turn are found only in specific habitats (4). In addition to this factor, there is an extremely unbalanced sex ratio in the Rafflesia flowers observed, with many more male than female flowers (4). Flower buds have a high level of mortality and only 10-18% go on to bloom, these only lasting for a few days; the chances of a male and female flower being in bloom at the same time in a close enough vicinity to be pollinated is therefore extremely slim (4). In addition to these inherent factors, there is widespread habitat destruction within much of the rainforested area of Southeast Asia and Rafflesia buds are also collected for traditional medicine, to treat fertility problems, in parts of their range (5).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
Rafflesia species are protected in a number of reserves within their range such as Mount Kinabalu National Park in Sabah on the island of Borneo (5). Habitat protection is one of the key factors in securing the future of this species and this magnificent flower is a huge draw to tourists, bringing much needed revenue to the area. More investigation into the life cycle of this unusual species is urgently needed to enable propagation and ex-situ conservation measures (3). Recent success in propagating R. keithii is an encouraging step forward in the preservation for future generations of one of the world's most astonishing plant species (4).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/rafflesia/rafflesia-spp/ |
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2015) |
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 Indonesia, Malaysia, Thailand and the Philippines.[1][not in citation given]
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 a 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 rotting flesh, 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 hermaphroditic 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.
Contents
Classification[edit]
- Species
- Rafflesia arnoldii
- Rafflesia aurantia
- Rafflesia azlanii
- Rafflesia baletei
- Rafflesia bengkuluensis
- Rafflesia cantleyi
- Rafflesia gadutensis
- Rafflesia hasseltii
- Rafflesia keithii
- Rafflesia kerrii
- Rafflesia leonardi
- Rafflesia lobata
- Rafflesia manillana
- Rafflesia micropylora
- Rafflesia mira
- Rafflesia patma
- Rafflesia philippensis
- Rafflesia pricei
- Rafflesia rochussenii
- Rafflesia schadenbergiana
- Rafflesia speciosa
- Rafflesia tengku-adlinii
- Rafflesia tuan-mudae
- Rafflesia verrucosa
- Unverified species
Comparison of mitochondrial DNA (mtDNA) sequences of Rafflesia with other angiosperm mtDNA indicated this parasite evolved from photosynthetic plants of the order Malpighiales.[2] Another study from that same year confirmed this result using both mtDNA and nuclear DNA sequences, and showed the three other groups traditionally classified in Rafflesiaceae were unrelated.[3] A more recent study found Rafflesia and its relatives to be embedded within the family Euphorbiaceae, which is surprising, as members of that family typically have very small flowers.[4] According to their analysis, the rate of flower size evolution was more or less constant throughout the family except at the origin of Rafflesiaceae, where the flowers rapidly evolved to become much larger before reverting to the slower rate of change.
Malaysian species[edit]
Species native to Malaysia include Rafflesia arnoldii, Rafflesia cantleyi, Rafflesia hasseltii, Rafflesia keithii, Rafflesia kerrii, Rafflesia pricei, and Rafflesia tengku-adlinii. R. arnoldii boasts the world's largest single bloom. Some endemic Malaysian species, such as R. keithii, begin blooming at night and start to decompose only two to three days later. The time from bud emergence to flowering is six to nine months. Male and female flowers must be open simultaneously for pollination to occur, hence successful pollination and fruit production are quite rare. In addition to habitat loss, these reproductive limitations are contributing factors to why many species are endangered. R. keithii is found along the eastern slopes of Mount Kinabalu in the Lohan Valley of Sabah.[1]Rafflesia tuan-mudae is endemic to only Gunung Gading National Park in Sarawak.
Loss of the chloroplast genome[edit]
Research published in the journal Molecular Biology and Evolution (January 2014)[1] reveals that one Philippine Rafflesia species from the island of Luzon, R. lagascae (formerly described as R. manillana) has lost the genome of its chloroplast and it is speculated that the loss happened due to the parasitic lifestyle of the plant. This discovery makes Rafflesia the first land plant without a chloroplast genome, which had once thought to be impossible. [2][3]
See also[edit]
- Amorphophallus titanum, similar smelling plant, sometimes known as "corpse flower".
- Parasitic plant
- Carrion plant
References[edit]
- ^ a b VJR Rafflesia Reserve, Forestry Department Sabah, Malaysia
- ^ Barkman, T. J.; S.-H. Lim, K. Mat Salleh, J. Nais (January 20, 2004). "Mitochondrial DNA sequences reveal the photosynthetic relatives of Rafflesia, the world's largest flower". PNAS 101 (3): 787–792. doi:10.1073/pnas.0305562101. PMC 321759. PMID 14715901. Cite uses deprecated parameter
|coauthors=
(help) - ^ Nickrent, D. L.; A. Blarer, Y.-L. Qiu, R. Vidal-Russell, F. E. Anderson. (October 20, 2004). "Phylogenetic inference in Rafflesiales: the influence of rate heterogeneity and horizontal gene transfer". BMC Evolutionary Biology 4: 40. doi:10.1186/1471-2148-4-40. PMC 528834. PMID 15496229. Cite uses deprecated parameter
|coauthors=
(help) - ^ Davis, C. C.; M. Latvis, D. L. Nickrent, K. J. Wurdack, D. A. Baum (January 11, 2007). "Floral gigantism in Rafflesiaceae". Science 315 (5820): 1812. doi:10.1126/science.1135260. PMID 17218493. Cite uses deprecated parameter
|coauthors=
(help)
Further reading[edit]
- Jamili Nais (2001). Rafflesia of the world. Kota Kinabalu: Sabah Parks. ISBN 983-812-042-1. OCLC 50043098.
License | http://creativecommons.org/licenses/by-sa/3.0/ |
Rights holder/Author | Wikipedia |
Source | http://en.wikipedia.org/w/index.php?title=Rafflesia&oldid=649204375 |