The roots of a plant function in many different ways, including absorbing nutrients and water, providing anchorage, and acting as a food storage site. A special type of root called a prop root also plays a substantial role in endowing certain plants with extra structural support. Prop roots do not grow from the embryo of a plant, but are rather secondary roots that develop from the tissues of other structures. These and other roots that are produced by stems or leaves are termed adventitious. Plants with prop roots often have very tall or branching stems that could be easily blown over by strong winds if not adequately propped up or are native to areas where the ground is particularly soft and unstable. Overall they are more common in tropical habitats than in temperate zones.