Leaf Background - In Botany, A Leaf Is An Above-ground Plant Organ Specialized For Photosynthesis. For This Purpose, A Leaf Is Typically Flat (laminar) And Thin, To Expose The Chloroplast Containing Cells (chlorenchyma Tissue) To Light Over A Broad Area, And To Allow Light To Penetrate Fully Into The Tissues. Leaves Can Store Food And Water, And Are Modified In Some Plants For Other Purposes. Photo