The world’s biggest flower, above, which grows more than three feet (a
metre) across and weighs 15lb (7kg), is most closely related to a
family with some of the smallest blooms, genetic analysis shows.
Rafflesia’s closest relatives are Euphorbiaceae which include
poinsettias, rubber trees, and castor oil plants, researchers from
Harvard University in Cambridge, Massachusetts, report in the journal Science.
The flower, which has a bud bigger than a football, is the only visible
part of a plant that has no leaves, shoots or roots and lives as a
parasite within a tropical vine. It smells of rotting flesh to attract
pollinating flies and is known as the corpse flower.
estimate that it took 46 million years to evolve from Euphorbiaceae.
Rafflesia takes nutrients from its host plant and has lost the plant
genes linked to photosynthesis. Charles Davis, who led the study, said:
“Rafflesia is unusual enough that it’s frankly been difficult to
imagine it fitting neatly into any plant family.”