'GEM' Cluster (IMAGE) University of California - Riverside Caption This photo shows a cluster of 'GEM' avocados on a tree. Credit Arpaia lab, UC Riverside. 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.