The World’s Largest Flower: Rafflesia Arnoldii

Rafflesia arnoldii:
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Rafflesiales
Family: Rafflesiaceae
Genus: Rafflesia
Species: Rafflesia arnoldii

Known as the largest individual flower on earth, the Rafflesia arnoldii is only naturally occurring in the rainforests of Borneo and Sumatra (where the other largest flower cluster, the Corpse Plant, lives) in the Indonesia Archipelago. The Rafflesia arnoldii species is the largest, with the flower reaching a diameter of around a meter and the weight coming in around 11 kilograms. Many of these varieties of Rafflesia are endangered or threatened. It is also one of two most distinctive plants on earth, the other being the aforementioned Corpse Plant.

Rafflesia arnoldii has a parasitic lifestyle, hosting off the Tetrastigma vine. It is similar in many ways to fungi as it has no leaves, roots or stems. It grows on tissue thread like strands on the host cells where it feeds on their water and nutrients. This plant, like the Corpse Plant, has a distinct aroma of rotting flesh on its reddish brown flowers. It is not one to be in one’s garden.

It is biologically a member of the plant kingdom; however, Rafflesia arnoldii does not have chlorophyll and cannot go through photosynthesis. Every member of the Rafflesiaceae family is this way. It is rarely pollinated due to the flowers being unisex and that sites usually will only produce all male flowers or all female flowers. Sites must be close together so that the flies that will aid in the transference of pollen and the flowers of opposite sexes must both be open and in bloom. It is difficult for everything to be in place so that pollination can occur. In addition to the above, there is a flower bud mortality rate of around 80-90%. Flower life span is appromixately a week. There fore, the flowers have to be in that brief 10% that will live, and must have two opposite sex flowers that are flowering in the same week closely together. It is this reason that the flower is so very rare in our population.

Rafflesia arnoldii is nearing extinction as the numbers are assumed to be declining due to its difficult in pollination and in the precise conditions needed for its growth. It is not known to be growing in any other area of the world unless it is on display in a museum setting. There are is a recreation effort in where botanists are trying to recreate the environment needed to grow this flower and to reproduce them. It has been unsuccessful but they continue to try.