The largest flower in the world – Rafflesia arnoldii

January 29th, 2011 | by lucy |

The largest flower in the world, produced by Rafflesia arnoldii, is a rarity, whose every flowering is a special occasion, a crowd-pleaser.  It also draws pollinating carrion flies by emanating a smell of rotting meat.  The Rafflesia arnoldii grows only in the most pristine rainforests of Indonesia, reaching an astonishing 1 metre in diameter.  The five “petals” are thick flaps, rusty red and mottled with white, reminiscent of a toadstool. They surround a gaping crater inside which the reproductive organs are found.

A parasite, Rafflesia arnoldii has no leaves, stem or roots, or chlorophyll, so relies on a host plant for food.  It germinates inside vines of the tetrastigma genus, where it exists as hair-like threads, similar to a fungus, and produces cabbage-like buds.  Few of these mature, as the plant is very fussy about climatic conditions, vulnerable to excessive rain as well as drought.  The chances of successful pollination are also slim, with the unisexual flowers few and far between, and a brief life-span of only 5 days.   Small rodents like tree shrews eat the fruit and disperse the seeds.

With their habitat also under threat, it’s no wonder this plant is endangered, though there have been some successful attempts to grow it in artificial conditions.

The plant and the genus were named after Sir Thomas Stamford Raffles, governor of Sumatra in colonial times, and with a strong interest in natural history – he founded London Zoo.

More excellent photos of Rafflesia arnoldii can be found here.

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