PROPAGATION OF WILD-DUCK FOODS. 



25 



and that the swans in particular feed extensively upon the plant. A 

 correspondent of the Biological Survey, Mr. George W. Russell, of 

 Gaston, Oreg., writes that the wapato is fed upon most by the diving 

 ducks, as the canvas-back, redhead, and bluebills (scaups), and that 

 they seek it whenever they are present in the country where it grows. 

 Prof. David Dale Owen, in his report of a geological survey of Wis- 

 consin, Iowa, and Minnesota, notes that these tubers afford much 

 nourishment to the larger aquatic fowls. The vernacular names swan 

 potato and duck potato that 

 have been applied to these 

 plants give further evidence 

 of their value to wild fowl. 

 Other local names are swamp 

 potato, muskrat potato, Chi- 

 nese onion, and water nut. 

 The Biological Survey has 

 found various parts of Sag- 

 ittaria plants in stomachs of 

 the following species of 

 waterfowl : Mallard, widg- 

 eon, green-winged teal, blue- 

 winged teal, spoonbill, pin- 

 tail, canvas-back, little blue- 

 bill, ruddy duck, Canada 

 goose, and whooping sWan. 



DESCRIPTION OF PLANT. 



The general relations of 

 stems, flowers, and tubers are 

 the same in the wapato 

 (fig. 23) as in the delta po- 

 tato, but the shape of the 

 leaves is entirely different. 

 Both Sagittaria latifolia and 

 8. ari folia have arrowhead- 

 shaped leaves. These vary 

 greatly in the length, width, and shape of the point and barbs and 

 in the degree of divergence of the latter. Various forms of leaves 

 are illustrated in figure 24. The wapato plant sometimes reaches a 

 height of 4 feet. The appearance of the flowers and seed balls is 

 much the same as in the delta potato. 



The tubers of S. latifolia (fig. 25) , from six to nine to the plant, are 

 formed on runners in the same manner as those of the delta potato, 



Fig. 23. — Young eastern plant of wapato with 

 single tuber. (Two thirds natural size.) 



