Zosteraceae - the Eel-grass Family
Diversity: Submersed marine herbs growing wholly submerged at depths of up to 50 m. Three genera with about 18 species.
Distribution: Worldwide and limited to sea coasts of subtropical to subarctic areas, of major importance, in terms of both ecology and economics, as primary producers in coastal habitats..
Floral structure: Flowers highly reduced, hydophilous, unisexual, and sessile in two rows along a spadix which is subtended by a spathe. Pollen grains filamentous, up to 2mm long.
Significant features: From
the broad perspective of plant evolution, a flowering plant lineage
has returned to the marine home. Reproductive adaptations
are highly specialized.
image from the Delta family description
More information on the Zosteraceae
and also the Seagrass