Cacti and succulents are plants that have adapted to the scarcity of rain water where they live, usually in a dry desert environment. They survive by having fibrous roots that spread out and dive deep into the ground, seeking out any underground water levels deep below. Any water is stored in stems or leaf cells that will expand to accommodate and hold as much water as possible. Cacti and succulents have a waxy coating that prevents water escaping from the plant.