Lichens on an Oak Trunk (IMAGE) Pensoft Publishers Caption Lichens growing on an oak trunk at the study site in central Spain. Credit Eduardo Morano, Raul Bonal Usage Restrictions CC-BY 4.0 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.