As an example of a typical isobilateral leaf, the leaf of maize may be studied. A cross section shows the following.
Epidermis:
There will be two epidermal layers upper and lower. The epidermal layers are uniseriate and composed of more or less oval cells arranged compactly. There is the deposition of a cuticle both on the upper epidermis as well on the lower epidermis. Besides the normal cells, the upper epidermis consists of special cells called bulliform cells or motor cells. These cells are larger than the other epidermal cells and are thin walled.
These help in the rolling of the leaves during dry weather. Leaves are amphistomatic (stomata are present on both the epidermal layers), Each stoma internally leads into a large substomatal air chamber. Mesophyll: It is undifferentiated. But the mesophyll cells below the upper epidermis may show a compact arrangement.
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Vascular bundles:
The veins are arranged parallely and are not interconnected. There are two pads of sclerenchyma supporting the vein. The vein itself is surrounded by the bundle sheath made up of parenchyma cells. Within the bundle sheath are present collateral vascular elements showing x/p arrangement.