49 BULLETIN: 862, U. S$. DEPARTMENT OF AGRICULTURE. 
WATERLILY FAMILY (NYMPHAEACEAE), 5.95 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 (Nymphaea advena) and the small yellow 
pondlly (Nymphaea microphylla) were identified; 10 contained 
seeds of white waterlilies, of which 2 species (Castalia odorata and 
C. tuberosa) 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, Ll, 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 (Cabomba 
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), 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 
(Ceratophyllum demersum). Thestomach 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 (Rumez 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 amphibium) 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 
19 For a full description of this plant and its seeds,see Bull. 205, U.S. Dept. Agr., pp. 9-12, 1915. 
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