“Most plants have their pores open during the day to take in carbon dioxide, and use sunlight as a catalyst for the reaction: Carbon dioxide + water becomes sugar + oxygen. But in the desert, plants with pores open during the hot days, lose much water through evapotranspiration.

“So, succulents use a modified version of photosynthesis called CAM (Crassulacean Acid Metabolism). CAM plants open their stomates only at night when it is cooler so there is less water loss. Because there is no sunlight to act as a catalyst, carbon dioxide is stored as an organic acid, principally Malic Acid (C4H6O5). Carbon dioxide is gradually released from the acid during the next day. CAM plants use about one-tenth the water to produce each unit of carbohydrate compared to standard photosynthesis. The price: a much slower growth rate.”