A 57-million-year-old leaf fossil found in eastern India could mean that sweet potatoes — long believed to be an American crop — are actually from Asia.
The leaf, which is part of the morning glory family of plants that includes sweet spuds, also suggests that the plant is much older than once thought. Previous fossil evidence found in North America led scientists to the now-disproven conclusion that the potatoes were only 35-million-years-old.
The 17 new fossils found in the northeastern state of Meghalaya, India also change the long-held beliefs about the origins of each of the 1,880 species in the group of morning glory, or Convolvulaceae, flowering plants.
“I think this will change people’s ideas,” the study’s co-author, Indiana University professor David Dilcher, told the News at IU Bloomington. “It will be a data point that is picked up and used in other work where researchers are trying to find the time of the evolution of major groups of flowering plants.”
But the ancient vegetation that grew millions of years ago may not have been the sweet potato currently known and loved by modern man. The fossilized leaves, although they share the same genus as sweet potatoes (Ipomoea), may not have produced a plant edible for people, according to the study.