The Incas survived on it. The Scots banned it on religious grounds. A French queen wore its flowers in her hair. And Peruvians today enjoy 4,000 varieties. Call it the “spud, tater” or just plain old potato (known in the science world as “Solanum tuberosum”). Thousands of years after its emergence on the windswept highlands of South America’s Andes, the lowly potato is conquering the world.