Bent Wood (IMAGE) DOE/Oak Ridge National Laboratory Caption Poplar stems (left) respond to bending stress by producing tension wood, which has characteristics desirable in a bioenergy feedstock. Electron micrographs from a comprehensive BESC study reveal how tension wood (bottom right) develops a secondary cell wall layer, in contrast to normal wood (top right). Credit ORNL Usage Restrictions None 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.