Yellow Flowers, Blue Sky (IMAGE) University of California - Davis Caption Black mustard (Brassica nigra) was studied in the Strauss-Lankau biodiversity study. Credit Photo credit: Sharon Strauss -- UC Davis 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.