A rare white flower from Japan, the Paris japonica, has been found to have the longest genome in the world, reports Associated Press's Raphael Satter. Researchers at Kew Gardens in London, who published their findings in Botanical Journal of the Linnean Society, say the flower has a genetic code 50 times longer than that of a human being. The human genome has about 3 billion base pairs, but this 12-inch flower turns out to have 150 billion base pairs, Satter says.
ScienceShot's Elizabeth Pennisi says if laid end to end, the Paris japonica genome would be taller than Big Ben. But, she adds, as impressive as this is, researchers say that big genomes tend to be a liability. "Plants with lots of DNA have more trouble tolerating pollution and extreme climatic extinctions — and they grow more slowly than plants with less DNA, because it takes so long to replicate their genome," Pennisi says, which perhaps explains why the flower is so rare.