The world's largest flower is Rafflesia arnoldii, a parasitic plant native to the rainforests of Sumatra and Borneo in Indonesia. The flower is five-petaled and dark red with white spots. It is a parasite on the Tetrastigma vine and is pollinated by flies. To attract its pollinators, Rafflesia arnoldii emits a scent like rotting meat, earning it the nickname "corpse flower."
While there are inflorescences that may appear to be a larger flower than Rafflesia arnoldii, they are technically made up of many small flowers. Therefore, only Rafflesia arnoldii can truly be called the largest flower. It can grow up to three feet (.91 m) long and weigh up to 24 pounds (11 kg).
Besides being the world's largest flower, Rafflesia arnoldii has many unusual attributes. The flower is the only visible part of the plant. There are no leaves, stems, or roots. The rest of the plant consists of threadlike fibers completely embedded in the host vine, from which Rafflesia arnoldii gets water and nutrients. Rafflesia arnoldii is similar to fungus in that only its reproductive structure is visible.
The world's largest flower is rare and difficult to find. It takes months to develop and lives for only a few days. Pollination is rare, as the flowers are unisexual, making the proximity between a male and a female plant essential to reproduction. They exist only in primary, or undisturbed, rainforest, as the host vine only grows in such areas. Rafflesia arnoldii has never been cultivated outside of its natural habitat.
Rafflesia arnoldii is currently endangered, as its habitat is being depleted. Environmentalists have attempted to recreate the natural environment of the world's largest flower in order to stimulate its recovery, but they have not yet been successful. Our best chance of preserving Rafflesia arnoldii is to preserve its original habitat, the rainforests of Borneo and Sumatra.