4 BULLETIN 58, U. S. DEPARTMENT OF AGRICULTURE. 
southern Illinois. Its actively 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 platyphylla 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 outlying 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. 
-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 will 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 anywhere in 
the southern half of the United States and may prove to be so farther 
north. 
