The Rafflesia arnoldii flower of Sumatra can grow to a metre across and weigh up to 11 kg. It produces no leaves, no stem, and no roots — the plant is a parasite that lives inside the tissues of the Tetrastigma vine and emerges only as the brief, enormous, smell-of-rotting-meat bloom that gives the species its public reputation. The bloom lasts five to seven days, attracts carrion flies as pollinators, and then collapses into a black slime.
Sir Stamford Raffles and the British naturalist Joseph Arnold found the first European-documented specimen on the small island of Pulau Lebar in Sumatra on 19 May 1818. Arnold’s journal entry of that day records the moment: “I rejoice to tell you that I happened to meet with what I consider as the greatest prodigy of the vegetable world.” He estimated the bloom at a yard across and immediately began the systematic botanical description.
He did not finish it. He contracted malaria during the same expedition and died at Padang on 26 July 1818, aged 36. Raffles forwarded Arnold’s notes and the preserved specimen to the Linnean Society of London, where Robert Brown completed the formal taxonomic publication in 1820. Brown’s choice of the binomial name — Rafflesia arnoldii — honoured both the expedition’s senior patron and its dead botanist.
The genus Rafflesia now contains approximately 28 recognised species, all parasitic on Tetrastigma vines and all distributed across the Indonesian-Malaysian rainforest belt. Most are classed as critically endangered. The 1820 type specimen survives at the Linnean Society’s London herbarium.