roots with rhizobia bacteria (IMAGE) Washington State University Caption A native Bird’s-Foot Trefoil plant (Acmisponwrangelianus), showing root nodules filled with nitrogen-fixing rhizobia bacteria in a chunk of soil. Credit Angeliqua Montoya, Washington State University Usage Restrictions For use only with stories associated with this press release License Original 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.