399 399
(a)Figure 14.1 A. Illustration of Vallisneria spiralis L. showing female flowers on long stalks and
freely floating male flowers, some of which are accumulating in the depression in the water’s surface
caused by the female flower. B. Tiny male Vallisneria flowers accumulating on top of a single large
female flower in a depression in the water surface caused by surface tension. Pollen then germinates
on the sticky stigmatic surfaces.
A is from Kausik, S. B. (1939), Pollination and its influences on the behavior of the pistillate flower in
Vallisneria spiralis. American Journal of Botany 26:207– 211.
B is from Wylie, R. B. (1917), The pollination of Vallisneria spiralis. Botanical Gazette 63:135– 145.