BULLETIN 58, U. S. DEPARTMENT OF AGRICULTURE. 



southern Illinois. Its activety growing delta (which is still apparently 

 in full vigor) made thick deposits of silt over some thousands of 

 square miles of this area while the remainder was being slowly ele- 

 vated. Sagittaria platypJiylla is so nearly confined in its distribution 

 to this ancient basin, and is so characteristic of the present delta, that 

 the name delta duck potato is eminently fitting. The outljring points 

 of the range of the plant as now known are San Antonio, Tex., Lake 

 City, Mo., Chattanooga, Tenn., and Mobile, Ala. (See fig. 3.) 



PROPAGATION. 



The delta duck potato undoubtedly can be propagated from seed, 

 but all things considered, transplanting the tubers is probably much 

 the better method. This insures a large percentage of success, the 



Fig. 3. — Range of the delta duck potato. 



plants will be larger, and as they will produce other tubers the first 

 year they are much more valuable. Extraordinary precautions to 

 prevent drying are not necessary, but the tubers should be kept cool 

 and well exposed to the air to prevent heating or fermentation. 



To plant, embed the tubers in mud bottom where the water is not 

 more than a foot deep, preferably not more than 6 inches. It is better 

 to err on the shallow side. The plant wdll grow thriftily on soil never 

 covered by water but which has plenty of moisture. In such situa- 

 tions, however, the tubers are not available to ducks unless over- 

 flowed in winter. The delta duck potato is not injured by a slight 

 amount of salt in the soil. The plant is probably hardy an3rsvhere in 

 the southern half of the United States and may prove to be so farther 

 north. 



