What is the World's largest flower.

The flower with the world's largest bloom is the Rafflesia arnoldii. This rare flower is found in the rainforests of Indonesia. It can grow to be 3 feet across and weigh up to 15 pounds! It is a parasitic plant, with no visible leaves, roots, or stem. It attaches itself to a host plant to obtain water and nutrients. When in bloom, the Rafflesia emits a repulsive odor, similar to that of rotting meat. This odor attracts insects that pollinate the plant.

Another enormous flower found in Indonesia is the Amorphophallus titanum, or Titan arum. It is also known as the "corpse flower" for its unpleasant odor. Like the Rafflesia, the Titan emits the smell of rotting flesh to attract pollinators. Technically, the Titan arum is not a single flower. It is a cluster of many tiny flowers, called an inflorescence. The Titan arum has the largest unbranched inflorescence of all flowering plants. The plant can reach heights of 7 to 12 feet and weigh as much as 170 pounds!

The flower is basically a pot, flanked by five lurid red-brick and spotted cream 'petals,' advertising a warm welcome to carrion flies hungry for detritus. Yet the plant is now hanging on to a precarious existence in a few pockets of Sumatra, Borneo, Thailand and the Philippines, struggling to survive against marauding humans and its own infernal biology.

Everything seems stacked against Rafflesia. First, its seeds are difficult to germinate. Then it has gambled its life entirely on parasitising just one sort of vine. This is a dangerously cavalier approach to life, because without the vine it's dead.

Having gorged itself on the immoral earnings of parasitism for a few years, the plant eventually breaks out as a flower bud, swells up over several months, and then bursts into flower. But most of the flower buds die before opening, and even in bloom Rafflesia is fighting the clock. Because the flower only lasts a few days, it has to mate quickly with a nearby flower of the opposite sex. The trouble is, the male and female flowers are now so rare that it's a miracle to find a couple ready to cross-pollinate each other.