Stomata and transpiration are of fundamental importance in the water relations of plants. It is evident that the loss of moisture in transpiration is equally as important as absorption of water by the root system in plant survival. Our mesophytic plants must have stomatal protection against excessive loss of moisture during drought. This is of paramount importance to us in our conservation work, where trees are being used as windbreaks, and to conserve moisture. Most of our knowledge regarding stomata has to do with herbaceous plants, as indicated by texts in plant physiology (Miller, 7, and others). Growth habits and therefore soil conditions are not the same for leaf formation on herbaceous plants as on trees. On trees most of the leaves grow simultaneously in the spring while on herbaceous plants they appear over a longer period. In herbaceous plants stomata are commonly on both leaf surfaces, but tree leaves have them usually only on the lower surface.