Green beans are an excellent source of vitamin C, vitamin K and manganese. Plus green beans are very good source of vitamin A (notably through their concentration of carotenoids including beta-carotene), dietary fiber, potassium, folate, and iron. And, green beans are a good source of magnesium, thiamin, riboflavin, copper, calcium, phosphorus, protein, omega-3 fatty acids and niacin.
Green beans and other beans, such are kidney beans, navy beans and black beans are all known scientifically as Phaseolus vulgaris. They are all referred to as "common beans," probably owing to the fact that they all derived from a common bean ancestor that originated in Peru. From there, they were spread throughout South and Central America by migrating Indian tribes. They were introduced into Europe around the 16h century by Spanish explorers returning from their voyages to the New World, and subsequently were spread through many other parts of the world by Spanish and Portuguese traders. Today, the largest commercial producers of fresh green beans include the United States, China, Japan, Spain, Italy and France.