DEVELOPMENTAL MORPHOLOGY OF THE ANDROECIUM AND GYNOECIUM IN RUPPIA-MARITIMA L - CONSIDERATIONS FOR POLLINATION

Ruppia maritima, widgeon grass, is an aquatic angiosperm common in sal t marshes. Although previous studies have covered general aspects of p ollination 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-li ke arrangement of the carpels directing pollen to the stigmatic region s, the buoyancy offered by presence of stomates and underlying spongy tissue in the carpellary outgrowth, the boomerang-like morphology of t he pollen grains which facilitates their aggregation, and the sheath e nclosing the anther are examined from the perspective of this speciali zed, hydrophilous pollination system. (C) 1997 Elsevier Science B.V.