Shade leaves are thinner than sun leaves

Have poorly developed palisade mesophyll

Light intensity is an important ecological factor affecting leaf anatomy. Shown are two views of cross-sectioned maple (Acer sp.) leaves. One is taken from the interior of the crown (top micrograph), representing a shade leaf which is thin and has a higher proportion of spongy mesophyll over poorly developed palisade mesophyll.

The sun leaf (bottom micrograph) shows a much more developed palisade mesophyll and reduced intercellular spaces in spongy parenchyma. Epidermal layers are not appreciably different in both leaves.