PROPAGATION OF WILD-DUCK POODS. 
23 
Bunning 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. 21) of this species shows the aptness of the name "wild 
potato." It should be explained, however, that normally the tubers are 
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 
BODOAM 
Fig. 21. — Tubers of delta potato. (About two-tbirds natural size.) 
southern Illinois. Its active!} 7 growing delta (which is still appar- 
ently 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 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. (fig. 22). 
