Man gets food from many kinds of plants--or parts of plants. We eat the leaves of cabbage and lettuce. We eat the flowers of broccoli and cauliflower plants. Corn, rice,and wheat--the chief sources of food in the world--are the seeds of plants. When we eat beets, carrots, or sweet potatoes, we are eating the roots of plants. Coffee, tea, and many soft drink get their flavor from plants.