Leaf Cells (image) University of California - Riverside Caption The lab of Zhenbiao Yang, a professor of cell biology at UC Riverside, has made a discovery that helps explain why leaf epidermal cells have jigsaw puzzle-piece shapes. Credit Yang Lab, UC Riverside. Usage Restrictions None 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.