Indonesia is home to some unusual plant species, including some of the world's largest, and most smelly, flowers. The Rafflesia arnoldi and Amorphophallus titanum, comprise the world's largest, and tallest flowers, respectively.
The R.arnoldi - named after Sir Stamford Raffles and his physician Joseph Arnold - reaches about one meter in diameter, and may weigh up to seven kilograms. It is a parasitic plant, growing on the woody liana, Tatrasigma, and in its non-flowering stage is almost invisible, consisting of microscopic filaments growing inside the liana. Several years may elapse before flowering begins, at which stage a tiny orange-brown, cabbage-like bud appears, gradually growing to its huge size.
the Rafflesia bud has formed
the bud begins to open
the bud opens to reveal is white-spotted petals
The flower fully open: the bloom lasts for a few days only. Even for field biologists, it is an uncommon sight.
Once open, the flower lasts only for a few days. The five dark red, leathery petals with white spots, surround a domed cavity with a capacity of about 6.5 liters. A central column is covered by a disc of spines, the function of which is not known. The foetid smell, like rotting meat, attracts flies to the plant.
If the female flower is pollinated, a spongy fruit develops which is about 15 centimeters wide, and contains thousands of seeds about one millimeter long. It is not known how these seeds are dispersed.
The Amorphophallus titanium grows from a corm of up to 50 centimeters diameter and weighing over 50 kilograms (the heaviest recorded was 75 kilograms). After a dormant period of several months, a bud will develop, growing at a rate of 4-20 centimeters a day. The fully-grown flower may be over three meters tall, the largest recorded being 3.3 meters.
The flower attracts dung and carrion beetles by exuding a rotten smell. They enter the chamber in the lower part of the flower, where they fertilise the female flower if they are carrying pollen from another bloom. On the way out, the insects are coated with pollen which they may then carry to another plant. Like the Rafflesia, the flowering period of the Amorphophallus is brief - two to three days - after which the flower collapses.