A GRAPHIC CHART FROM GREATEST SHOWING THE BEST GREENS FOR NUTRITION. 

Not all leafy greens will build a super-nutritious salad. In fact, America’s favorite lettuce, iceberg, ranks the lowest in nutritional value across the board (96 percent water content will do that!). Turbo-charged spinach, on the other hand, boasts nearly twice the recommended daily value of vitamin K, half the recommended value of vitamin A, and ample  amounts of calcium and iron. Clearly, Popeye was on to something. Click image to make it larger and printable.