C₄ plants show kranz anatomy, i.e., the mesophyll is undifferentiated and its cells occur in concentric layers around vascular bundle, which is surrounded by large sized bundle sheath cells, in a wreath like manner. In this type of plants, the initial fixation of CO₂ occur in mesophyll cell. The primary acceptor (phosphoenol pyruvate) combines with CO₂ to form oxaloacetic acid which later reduces to malic acid. Malic acid is then translocated to bundle sheath cell for further decarboxylation.