There aren’t many, as compared with what has come from Mexico, Central America, and the Old World. Blueberries, Hickory and Pecan nuts, cranberries, persimmons, and paw-paws — not a large list. But then there is the sunflower, mainly Helianthus annuus. Somehow seeds of this American plant made their way across the Atlantic and farmers and plant-breeders in Russia and the Ukraine learned that the tall plant was ideally suited to the climates there.
Farmers found that sunflower seeds are a great source of cooking oil, when they are squeezed hard enough. This NPR story tells the tale very well: