Rafflesia flower is known as the biggest flower in the world. Its scientific name is Rafflesia arnoldii, derives from the name of first people who discovered this flower, Thomas Stamford Raffles and Dr. Joseph Arnold. The size ranges from 60 cm till 120 cm when blooming. It grows in Java, Sumatra, Borneo, Malaysia and The Philippines, usually in rain-forest environment. Rafflesia has never been successfully cultivated.
Rafflesia is like parasite, it grows from Tetrastigma root, from the family of grape. It appears from the ground in small bud and then grows bigger over 1.5 years and then blooms for 7 days. The first time i see it, it was so strange and beautiful, unlike any flower i have seen in my life, it has no leaves, it is on the ground and it is gigantic, red, thick, with white dots all over the 5 petals and spikes inside.
The flower has rotten meat smell, that it attracts female carrion flies. On Day 1 and Day 2 bloom, the smell is very subtle, and we need to sniff it close to smell it. However on Day 3 and more it smells stronger. The smell maybe was caused by the heat generated by the flower , similar thing happened to skunk cabbage (Harvard magazine.com).
Pollination of Rafflesia is very difficult and rare. Maybe that is why that this flower is not easily found. Here are the factors the scarcity of Rafflesia pollination: one flower can be male or female only, flowers do not bloom at the same time, flower blooms in few days only.
Rafflesia’s pollen is not powdery but viscous fluid, that attached and dries on carrion flies backs. Presumable it is viable for long time and it flies few miles to female flower and it rub its back in the stigma of the female flower. And when the flower finishes blooming will create seeds which takes 6-8 months. And then how the seeds infect the new host plant? It is still remains a mystery.
A theory says that ants spread the seed, and then put it in the vine, or the ants attracted to sugar water from the bark of the vine caused by animals, or ants carry seeds and stored nearby the vine roots and infected the host itself. This can be true as the vine has broken bark, which might be easily infected by Rafflesia seed. In West Sumatra, the local people call Tetrastigma as paca paca means broken due to scratched surface.
And it is already known that the flower has an organ called haustorium which functions to take nutrient and water from the host. Vine is known for having much water in it. And it takes much water to make the flower to bloom. If we touch the petals we can feel it contains much water. Flower does not grow on any Tetrastigma, but usually Tetrastigma located nearby water source in primeval or secondary forest.
Other mystery of the flower is regarding its relationship with the host plant. The flower is very dependent to then host that they do not do photosynthesis. According to a research, there is a massive gene transfer between the two organism without sex. This case is very unusual. Horizontal gene transfer is mostly hereditary. The host contributed 2-3 percent to the genes in cell nucleus, and 50 percent of the genes that govern energy production. This is probably why Rafflesia is invisible to the host as they share so much genes that the difference between them is not distinctive. The gene transfer seems like a mean to camouflage .