Ruppia maritima, widgeon grass, is an aquatic angiosperm common in salt marshes. Although previous studies have covered general aspects of pollination and floral development, little information is available on the functional aspects and development of the androecium and gynoecium in relation to pollination. Using the techniques of scanning electron microscopy and thin sectioning, this study focuses on the functional morphology of the gynoecium, anthers, and pollen grains. The funnel-like arrangement of the carpels directing pollen to the stigmatic regions, the buoyancy offered by presence of stomates and underlying spongy tissue in the carpellary outgrowth, the boomerang-like morphology of the pollen grains which facilitates their aggregation, and the sheath enclosing the anther are examined from the perspective of this specialized, hydrophilous pollination system.