Photographed in this picture are succulents and cacti. Succulents and cacti are commonly identified as CAM Plants. CAM stands for Crassulacean acid metabolism. Another, perhaps more common name, is CAMPhotosynthesis. Crassulacean acid metabolism is a carbon fixation pathway that some plants evolved to help adapt to barren conditions. Plants that are in full CAM have the stomata in their leaves closed during the day, but open at night to retrieve carbon dioxide.
Succulents are CAM Plants because the inhabit features like Crassulacean acid metabolism to minimize the loss of water.