_​C₄ plants are specialized plants for better CO₂ assimilation found in a hot environment. They have characteristic leaf anatomy called kranz anatomy showing two distinct chloroplast containing cells mesophyll and bundle sheath cells. Mesophyll cells are located very near to bundle sheath cells and are the site for the C₄ cycle. CO₂ is fIrst fixed as a 4 carbon compounds oxaloacetic acid by the action of PEP carboxylase. The second carboxylation event occurs in the stroma of chloroplast of bundle sheath cells through the C₃ cycle.