Mesembryanthemum crystallinum
Mesembryanthemum crystallinum is a prostrate succulent plant native to Africa, Sinai and southern Europe, and naturalized in the New World. The plant is covered with large, glistening bladder cells or water vesicles, reflected in its common names of common ice plant, crystalline ice plant or ice plant.
Mesembryanthemum crystallinum
Silhouetted stem
Flowers and leaves
Close-up of flower
Crassulacean acid metabolism
Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions that allows a plant to photosynthesize during the day, but only exchange gases at night. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but they open at night to collect carbon dioxide and allow it to diffuse into the mesophyll cells. The CO2 is stored as four-carbon malic acid in vacuoles at night, and then in the daytime, the malate is transported to chloroplasts where it is converted back to CO2, which is then used during photosynthesis. The pre-collected CO2 is concentrated around the enzyme RuBisCO, increasing photosynthetic efficiency. This mechanism of acid metabolism was first discovered in plants of the family Crassulaceae.
The pineapple is an example of a CAM plant.
Overnight graph of CO2 absorbed by a CAM plant
CAM is named after the family Crassulaceae, to which the jade plant belongs.
Cross section of a CAM (Crassulacean acid metabolism) plant, specifically of an agave leaf. Vascular bundles shown. Drawing based on microscopic images courtesy of Cambridge University Plant Sciences Department.