Side by side (IMAGE) American Society of Agronomy Caption Two types of shrub willow: Fabius (left) and Preble (right). The willow shoots are one year old; the crowns five years old. Credit Armen Kemanian Usage Restrictions For use with this story only. 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.