CHAPTER XX.

PLATE XXXV.—VALLISNERIA.

FIG. 1. Valisneria spiralis. The female plant, the flowers of which are purple. This is drawn from a specimen in the posses sion of Dr. Ogle.

FIG. 2. The male plant, producing white flowers; these when mature rise like air bubbles, and suddenly expanding when they reach the surface of the water, float about in such abundance as to cover it entirely. "Thus their pollen is scattered over the stigmas of the first mentioned blossoms, whose stalks soon afterwards resume their spiral figure, and the fruit comes to maturity at the bottom of the water."

FIG. 3. One of the separated male flowers magnified.