English oak leaf pores or stomata (Quercus robur) Science Image

Ref: 80200288



English oak leaf pores. Coloured scanning electron micrograph (SEM) of stomata on the underside of a leaf from an English oak (Quercus robur) tree. Stomata are pores that open and close in order to regulate gas exchange in a plant. A pair of specialized cells known as guard cells, control the size of the opening by swelling to close the pore and shrinking to open it. Stomata are found mainly on the underside of leaves. Magnification: x347 when printed 10 centimetres wide.