Question 6
In Vallisneria, what actually makes the journey across the water?
The right answer is the one marked above.
The whole staminate flower. When mature it detaches from the plant and floats, drifting until it reaches the stigma of a pistillate flower.
This is the one agent where the pollen itself is not what travels. The pistillate flower stays put, held right at the surface on a long stalk. The pollen tube does not appear until after pollination, and it grows inside the gynoecium.