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 



