Many people I've met believe that plants are made up of soil--that the tree outside your house, for example, is mostly made from the soil in which it grew. That's a common mistake. That tree is mostly made up of one of the gases in our air (carbon dioxide) and water (hydrogen and oxygen). Trees are solidified air and sunlight.
Source: The Last Hours of Ancient Sunlight: Waking Up to Personal and Global Transformation
Contributed by: Siona