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, 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.
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.
