Two stomata can be seen, one on either surface of this leaf section. Stomata are really plant pores which enable gas exchanges to take place, and water vapour to be lost. This has the benefit of moving water up the plant in a process called transpiration. The stoma (singular) can be seen in fine detail here surrounded by guard cells-{1}. The pore -{2} and the guard cells make up a single stoma. There may be as many as 6 million per typical leaf! The area just inside the internal structure of the leaf and below the stoma is the air space -{3} which brings carbon dioxide very close to the palisade parenchyma tissue; so diffusion gradients are maintained over the small distances between stomata and palisade parenchyma.   This is a much higher magnification of a stoma taken through an ordinary optical microscope. You can clearly see the open pore and the guard cells either side of the gap. Remember that you are looking at a section cut down through the leaf. Stomata should also be viewed by looking at a leaf surface under a microscope from above. This will help you understand the true shape and structure of stomata.
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