Crassulacean acid metabolism is abbreviated as CAM. CAM metabolism is a special feature of succulent plants. In 1804, De Saussure first observed that ficus bengalensis has more organic acids at night and less organic acids during the day. This occurs in many succulents of the Crassulaceae and Cactaceae families. Bryophyllum, Annanus, Orchid, Cractus, Crassula, Sedum etc. show decrease-increase in acid content. In the leaves of these plants, organic acid and pH decrease during the day and organic acid and pH increase at night. So at night the stomata are open and photosynthesis takes place. The increase in the amount of organic acids at night is called dark acidification and the decrease in the amount of organic acids at night is called light deacidification. The steps in the CAM process are similar to the C4 cycle.