Navel oranges have a thinner skin than many other oranges and are sweet and seedless. “They’re the standard everybody knows and eats,” says Valerie Aikman-Smith, chef and co-author of Citrus ...

Humans, however, have brought a great winnowing: Out of thousands of wild types, only a few dozen have become commercial behemoths like the navel ... oranges that are sweeter, seedless, and ...