42 BULLETIN 862, t T . S. DEPARTMENT OF AGRICULTURE. 



WATERLILY FAMILY (nYMPHAEACEAe), 5.9'5 PER CENT. 



Seeds of waterlilies are quite frequently eaten by ducks. Twelve 

 of the wood ducks had eaten seeds of yellow pondlilies, of which 

 two species, the cowlily (Nympliaea advena) and the small yellow 

 pondlily (Nympliaea micropTiylla) were identified; 10 contained 

 seeds of white waterlilies, of which 2 species (Castalia odorata and 

 C. tuherosa) were identified; and 11 contained seeds of water shield 

 (Brasenia schreberi). Of the latter, one contained 380 seeds; and 

 the stomach and distended gullet of a wood duck taken near Chi- 

 cago, 111., held 577 seeds of a white waterlily (Castalia tuberosa), 

 with fragments of several more, in addition to other items. Two 

 stomachs from southeastern Missouri contained quantities of the 

 remains of stems and leaves of Carolina water shield (Cahomba 

 caroliniana) . 



NETTLE FAMILY (URTICACEAE), 4.75 PER CENT. 



The nettle family of plants was represented in the wood duck 

 stomachs chiefly by the seeds of water elm (Planera aquatica) , 19 which 

 had been taken by 66 of these ducks. Many ducks in Louisiana 

 had gorged themselves upon these large seeds, their gullets and giz- 

 zards being crammed. One wood duck had devoured nearly 300 

 at its last meal. A series of 13 gizzards from Avoyelles Parish. La., 

 contained seeds of water elm to the average extent of over 48 per cent, 

 most of the remainder of the food consisting of the seeds of coontail 

 ( Ceratopliyllum demersum) . The stomach of a duck from southeastern 

 Missouri was nearly filled with the seeds of another elm ( Ulmus sp.). 

 Another, from Alabama, contained the remains of several red mul- 

 berries and eight of the hard drupes of hackberries (Celtis sp.), both 

 of which belong to this family of plants. The small seeds of false 

 nettle (Boehmeria cylindrica) were present in three stomachs. 



SMARTWEEDS (POLYGONACEAE), 4.74 PER CENT. 



In addition to a few seeds of dock (Rumex sp.), which were found in 

 seven gizzards, and unidentified smartweeds, in 17, ten species of 

 smartweed seeds were identified as having been eaten by the wood 

 ducks. Of these, water smartweed (Polygonum ampMlium) and 

 mild water pepper (P. hydropiperoides) were the most commonly 

 taken. The largest number of smartweed seeds found in any one 

 wood duck stomach was taken from a bird collected in Avoyelles 

 Parish, La., which had eaten over 1,100 of the small black seeds of 

 Polygonum opelousanum. 



coontail (Ceratophyllum demersum), 2.86 per cent. 



Coontail is a rootless, submerged plant, the much-branched stems 

 of which bear bushy masses of small whorled leaves. Near the ends 



18 For a full description of this plant and its seeds, see Bull. 205, U. S. Dept. Agr., pp. 9-12, 1915. 



