22 
BULLETIN 465, U. S. DEPARTMENT OF AGEICULTURE. 
summer, and when ripe are brown and nearly half an inch in diame- 
ter. They are easily crushed, separating into hundreds of thin tri- 
angular seeds. 
Fig. 20. — Delta potato. (Scale is 18 inches long. 
The tubers are of irregular globular shape and vary up to an inch 
in diameter. They are forme;! at the ends of runners (thicker than 
the fibrous 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. 
