Characteristics of Leaves Leaves are metabolic factories equipped with photosynthetic cells. Leaves vary enormously in shape, size, texture and surface. Monocot leaves tend to have a flat surface, like a knife blade, the base of which encircles and sheaths the stem. Leaf Internal Structure Leaves represent a large surface area that is exposed to sunlight and carbon dioxide. Photosynthetic parenchyma cells are located in the mesophyll.
Air spaces participate in gaseous exchange.
Stomata are located mostly on the lower epidermis. Origin of Leaves Leaves develop on the flanks of the tips of stems as outgrowths of apical meristems. A node is the point where a leaf or leaves attach to the stem. An internode is the region on the stem between two nodes. A bud is an undeveloped shoot of mostly meristematic tissue covered by modified leaves.