How do cacti conserve water in the desert?

Cacti conserve water in the desert through several key adaptations. Their thick, waxy skin prevents water loss by reducing transpiration, while their stems are modified to store large amounts of water. Cacti also have shallow root systems that quickly absorb any rainfall that does occur, and they can perform photosynthesis during the cooler hours of the day or night to avoid water loss through evaporation. Their spines, which are modified leaves, also help reduce water loss by providing shade and deterring herbivores.