Plant pipe cell -lignin (IMAGE) Stockholm University Caption Plant pipe cell reinforced with lignin is highly resistant to negative pressure in contrast to the other flattened cells around. Photo using Scanning Electron Microscopy (SEM): Cheng Choo Lee Credit Photo using Scanning Electron Microscopy (SEM): Cheng Choo Lee Usage Restrictions None License Original 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.