The plants of the Desert habitat area have adapted to its dry, hot extremes by using both physical and behavioral mechanisms. Plants that have adapted by altering their physical structure are called xerophytes. Xerophytes, such as cacti, usually have special ways of storing and conserving water. They often have few or no leaves, which reduces water loss. Phraetophytes are plants that have adapted to living in the desert by growing very long roots, allowing them to get their moisture deep within the earth, at or near the water table. Perennials (plants which live for years) and annuals (plants which live one season) also have behavioral adaptations. The perennials survive by remaining dormant during the dry periods and come to life when water is available. Annuals germinate after heavy rain and complete their reproductive cycle quickly. They bloom for a few weeks in spring. Their seeds remain dormant in the soil until the next year’s rain.