Roselle powder (IMAGE) RMIT University Caption Freeze dried roselle flowers crushed into a powder. The powder is in a petri dish with a metal spoon scooping up some of the powder. Credit RMIT University 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.