Plants and Human Welfare
All life on Earth runs on sunlight by the use of light energy in the process of photosynthesis. The food we eat is either plant or animal, and the energy derived from this food is easily traced back through the food chain to green plants. While there are nearly 500,000 species of known plants, all of the food on which people rely comes from twenty species, and 80 percent of our food comes from six species. These a re all grasses: wheat, rice, corn, barley, rye, and oats. The grass family feeds the world.All civilizations have depended on the cultivation of grasses. The peoples of ancient Babylonia, Egypt, Rome, and Greece grew wheat, barley, rye, and oats. In China and Japan, rice is the staple food. The pre-Columbian peoples of America-the Incas, Mayas, and Aztecs-looked to corn for their daily bread.