Grass Stomata Video (VIDEO) Carnegie Institution for Science This video is under embargo. Please login to access this video. Caption 3-D animation of a four-celled grass stomatal complex imaged by confocal microscopy. Two central, dumbbell-shaped "guard cells" are flanked by one extra cell on each side, the 'subsidiary cells'. The stomatal complex is surrounded by elongated epidermal cells. Stomata act like cellular leaf valves that balance carbon dioxide uptake and water vapor loss and the four-celled, grass-specific form allows grasses to do this very efficiently. The 3-D reconstruction is depth color coded. Credit Dominique Bergmann and Michael Raissig Usage Restrictions With credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.