FIVE IMPORTANT WILD-DUCK FOODS. 3 
flowers in whorls of three, and the individual flowers each have three 
white petals and a yellow center. The petals soon fall and the small 
green balls of immature seeds remain. These enlarge during the 
summer, and when ripe are brown and nearly half an inch in diameter. 
They are easily crushed, separating into hundreds of thin triangular 
seeds. 
The tubers are of irregular globular shape and vary up to an inch 
in diameter. They are formed at the ends of runners (thicker than 
the roots) and bear on the side opposite the attachment to, the runner 
a scale-sheathed bud which may be an inch or more in length. Run- 
Fig. 2.— Tubers of the delta duck potato. (About two-thirds natural size.) 
ning around the body of the tuber are two or three darker lines from 
which originate fibrous sheaths. A glance at the illustration of the 
tubers (fig. 2) of this species shows the aptness of the name wild 
potato. It should be explained, however, that normally the tubers 
would be more widely separated than is the case with those on this 
particular specimen, which was grown in a flower pot. 
DISTRIBUTION. 
In ancient times the Mississippi River emptied into a vast bay 
which extended at least as far north as the region now known as 
