Crassulacean Acid Metabolism (CAM) photosynthesis is a specialized form of photosynthesis that allows plants to thrive in arid environments. CAM plants, such as succulents and some orchids, open their stomata at night to minimize water loss and store carbon dioxide as malic acid in vacuoles. During the day, the stomata close to conserve water, and the stored carbon dioxide is used for photosynthesis.
