A perfect, very common example of a CAM plant is a cactus like pictured below. CAM plants, also known as Crassulacean Acid Metabolism plants, are adapted to extremely hot and dry environments. These CAM plants only keep their stomata open at night when it is cooler. If they were open during the day, they would lose too much water. Unlike C3 and C4 plants, CAM plants use much less water due to the fact that they only have their stomata open at night. The CO2 collected at night when the stomata are open is stored and used in photosynthesis during the day. Pineapple is another example of a CAM plant that is agriculturally important.