Mulberry (IMAGE) Washington University in St. Louis Caption This is an impression of a mulberry leave, a sign of silk cultivation, found at the Sanyangzhuang site. Credit Henan Provincial Institute of Cultural Relics and Archaeology 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.