Water Fern and Cyanobacterium Symbiosis (IMAGE) Rutgers University Caption This is symbiosis between the water fern Azolla and the cyanobacterium Anabaena that is vertically inherited via the fern mega-spore apparatus. This is a transverse section showing the megaspore (M), floats (F), and cyanobacteria (C; red region). Credit Image prepared by H. Schneider. 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.