Wheatgrass Seed (IMAGE) American Society of Agronomy Caption MN-Clearwater wheatgrass seed, whose grain threshes freely from the hulls 63% of the time. Credit Brett Heim 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.