Anatomical and SEM observation of the inflorescence showed that eelgrass was a monoecious plant, the male and female flowers were alternately arranged on the inflorescence. Each anther had one chamber, and the pollen of eelgrass was filamentous, with no exine sculpturing, inaperturate. The carpel contained one ovule and two stigmas, there were filaments on the epidermal cells in front of the carpel. All the characters showed that eelgrass had already adapted to submarine life.