THIERRY BERROD, MONA LISA PRODUCTION / SCIENCE PHOTO LIBRARY THIERRY BERROD, MONA LISA PRODUCTION / SCIENCE PHOTO LIBRARY
Pine needle stoma. Coloured environmental scanning electron micrograph (ESEM) of a stoma (red) on the surface of a pine needle (Pinus sp.). Stomata are pores that are the site of gaseous exchange in the plant. The opening and closing of the stomata is controlled by semicircular guard cells. When the guard cells are turgid the stomata are open and when they are flaccid the stomata are closed.
Model release not required. Property release not required.