Among the rafflesia family of flowers are twenty different kinds. Rafflesia arnoldii is the one of them who grows largest. In fact it's considered the flower with the largest bloom in the world. It's home in the tropical rainforests of the Malay Archipelago. The size of a specimen of rafflesia arnoldii can reach a meter in diameter and a weight up to eleven kilograms.
Rafflesia arnoldii is a parasitic plant which does not grow any leaves or roots. It neither produces chlorophyll. It consists only of the bloom and it's bottom site of fungi strings who are rooting in the host plant and supply the plant with nourishment. The host plant for rafflesia is exclusively 'tetrastigma', a liana of the grape family, a kind of wild vine.
The plant forms tiny, little buds who develop over about a year. The buds grow slowly and look like cabbages. When the buds finally open, the flower appears in it's full 'glory'. Then the foulish smell appears to attract insects for pollination. The blooming time of a rafflesia is not more than a couple of days. The pollinated plant produces thousands of seeds inside the flower. These seeds are distributed in the forest by squirrels (treeshrews). Then the blossom turns from red into brownish colours and decays.
Remarkable is the strong smell of the flower. It produces a scent which imitates the stench of a rotting corpse. That's why the rafflesias are also sometimes called 'corpse flowers'. The stench attracts mostly flies but also certain beatles who come to feed themselves and transport the pollen.
Rafflesia arnoldii is a very rare plant. To grow it requires an intact habitat in the tropical rainforests of Southeast Asia. The massive destruction of the rainforests in Indonesia and Malaysia lead to the extinction of millions over millions of species. Rafflesia arnoldii is an endangered species as well.
A rafflesia arnoldii in Pananjung Pangandaran nature reserve. It's already in a state of decay. Image by Mr. Ona, an official in the park, 2012
Since the grand flower is often seen as a mysterious being, it became a kind of legend and a tourist attraction. Some guides in national parks as for example in Pangandaran, promise tourists to show them a blooming rafflesia. However, the flower tourism does the plants no good; people who frequently penetrate the jungle on the search for whatever do harm the ecosystem. They harm the forest floor by walking on it and disturb animals. They often harm plants and wildlife directly and on purpose and drop litter in the nature. Rafflesia's are not easy to find in the jungle.
Rafflesia arnoldii is named after Stamford Raffles (1781-1826) and the British botanist Joseph Arnold (1782-1818). They got a specimen which was brought to them by a Malay servant in 1818. Arnold started to describe the flower and started an sketch which he couldn't finish. He died soon after, due to a tropical fever. Stamford Raffles' wife finished the sketch and coloured it. It was sent to London. The species was officially described in 1821 by Robert Brown (1773-1858) from the British Museum and the Linnean Society.
However, the first botanist who found a specimen of a rafflesia was the French Louis Auguste Deschamps (1765-1842). He came to Southeast Asia as a member of a scientific expedition and spent three years on Java. In 1797 he found a specimen of what was later called rafflesia patma.
Together with two other flowers, the moon orchid and the white jasmine, rafflesia arnoldii has been declared as a 'national rare flower' of Indonesia.