Rafflesia is a
genus of
parasitic flowering plants. It contains approximately 27 species (including four incompletely characterized species as recognized by
Willem Meijer in 1997), all found in southeastern Asia, on the
Malay Peninsula,
Borneo,
Sumatra, 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
endoparasite 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" (but see below). The vile smell that the flower gives off 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 apparently eat the fruits and disperse the seeds.
Rafflesia is an official state flower of
Indonesia, also
Sabah state in
Malaysia, as well as for the
Surat Thani Province,
Thailand.
The name "corpse flower" applied to
Rafflesia is 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 still distantly related.
Rafflesia arnoldii has the largest
single flower of any flowering plant, at least when one judges this by weight.
Amorphophallus titanum has the largest
unbranched inflorescence, while the
Talipot palm (
Corypha umbraculifera) forms the largest
branched inflorescence, containing thousands of flowers; this plant is monocarpic, meaning that individuals die after flowering.