How do desert plants survive long periods without rain?

Desert plants have evolved diverse physiological and structural adaptations to survive long periods of moisture shortage and thrive during infrequent wet periods. These strategies include:1

• Water Storage: Many succulents, such as cacti and agaves, possess thick, fleshy stems or leaves that store water for use during dry times.23
• Metabolic Efficiency: Many desert plants utilize crassulacean acid metabolism (CAM). Unlike most plants, CAM species keep their stomata closed during the hot day to prevent water loss and open them at night to collect carbon dioxide.24
• Dormancy and Ephemeral Growth: Perennial plants may become physiologically inactive until moisture returns. Ephemeral plants survive as dormant seeds, germinating, growing, and reproducing rapidly during the brief window following a rain.15
• Structural Modifications: Plants may feature deep or broad root systems to reach groundwater, or physical traits like waxy coatings, hairy surfaces, or reduced leaf size to minimize transpiration. In some species, spines protect against herbivores and help collect condensed water vapor.316