The tropical Asian plant, which can have flowers measuring up to 3 feet, belongs to a group that bears tiny blooms, the BBC said Friday. Rafflesias are a group of plants that has about 50 individual species.
Using DNA analysis, Harvard botanists determined the rafflesias belong to the Euphorbiaceae family, which includes the rubber tree, castor oil plant and the cassava shrub.
The plants' features were a puzzle, the Harvard University research team reported in Science. They're rootless, leafless and stemless. They're also parasitic, thriving in the tissue of the tropical grape vine, gorging on the vine's nutrients.
Lead author Charles Davis, assistant professor of organismic and evolutionary biology at Harvard, called the plants' botanical family a "big shocker."
Davis' team said they believe the blooms evolved at an accelerated pace, estimating the flowers developed from a minute 0.08 inches to their enormous size.
Such large blooms provide the plants an advantage, scientists said. They rely on flies for pollination, so the bigger the blooms, the further their alluring stench can carry.