Restoring the American Chestnut (IMAGE) American Society for Horticultural Science Caption Tissue-cultured American chestnut shoots are shown in a post-rooting medium containing activated charcoal. Experiments showed that activated charcoal enhanced root growth but slightly decreased shoot tip survival. Credit Photo courtesy of Allison Oakes. 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.