2O2 



Minnesota Plant Life, 



FIG 



Arrowhead. After Britton 

 and Brown. 



plant is pulled up by the roots it will be discovered very possibly 



that there are broad or slender grass-like leaves submerged in 



the water. In one Minnesota va- 

 riety the arrow-headed leaves float 



upon the surface of the water like 



those of the pond-lilies, but more 



commonly they are not natant. In 



some species all of the leaves are 



grass-like or slender, while the 



plants must be recognized rather by 



their characteristic flowers. A large 



number of separate carpels are pro- 

 duced in each flower and when it 



ripens the group of carpels become 



a more or less spherical head. In 



each of the closed carpels or ovaries 



is a single erect seed slightly curved. 



In Minnesota there are at least six species of arrowheads. 



Eel-grasses. A fifth fam- 

 ily in this second order in- 

 cludes the well-known eel- 

 grass, the plant which gives 

 so delicate a flavor to the 

 flesh of the canvas-back 

 duck, which is very fond of 

 pulling it and eating the 

 soft parts of the leaves and 

 stems. There is something 

 very remarkable about the 

 way in which this plant pro- 

 duces its flowers. The gen- 

 eral plant-body consists of a 

 (short stem rooted in the 

 mud on the bottoms of lakes 

 near their edges. The leaves 



FIG. 81. Eel-grass. After Britton and Brown. are long, graSS-Hke and of a 



diaphanous translucent green, rarely floating at the surface, 

 more generally submerged and ascending. The pistillate flow- 

 ers are produced at the end of a very long, slender spiral stem 



