DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY
False-colour scanning electron micrograph of the underside of a leaf from a holly bush, Ilex aquif- olium, found growing in the countryside, where the air is relatively unpolluted. E810/153). The image shows a number of stomata, the pores in the leaf surface through which gases pass across the otherwise impermeable epidermal layer. Stomata allow atmospheric carbon dioxide into the leaf and molecular oxygen out. Each stoma has two 'guard' cells (here coloured yellow) which expand or contract to regulate the passage of gases to suit the requirements of the plant. Holly leaves have around 2000 stomata per square centimetre. Magnification x500 at 6x4.5cm size.
Model release not required. Property release not required.