Dwarf birch (IMAGE) University of Bonn Caption The dwarf birch (shown here) loses its foliage in winter, but the crowberry is evergreen. Credit © Roland Pape / University of South-Eastern Norway Usage Restrictions Please use this image only in connection with the 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.