May, 1943 
stomachs analyzed from Clear Lake 
was proportionally larger than at lakes 
at which Walter’s millet did not rank so 
high. Low & Bellrose (ms.) found that, 
in 1941, wild and Japanese millets pro- 
duced considerably greater quantities 
of seed per unit of area than did Walter’s 
Fig. 4.—Largeseed smartweed (Polygonum 
pennsylvanicum), in contrast to nodding smart- 
weed, has thick, erect spikes. This and other 
moist-soil smartweeds constitute a group that 
appears to be slightly more valuable than the 
nutgrasses, but less valuable than the millets, 
as a source of food for migratory waterfowl. 
millet. However, in that year, high 
water so retarded growth of. Walter’s 
millet that plants were only 2 to 5 feet 
high, whereas in 1939 and 1940 they 
were 7 to 9 feet high. The taller plants 
had considerably larger inflorescences 
and therefore produced much more seed. 
Nutgrasses, fig. 3, are in third posi- 
tion in table 3. Although the index 
BELLROSE & ANDERSON: Duck Foop PLANTS 
423 
rating derived from data obtained in all 
3 years places this group, Cyperus ery- 
throrhizos, C. strigosus and C. esculentus, 
third in value, we believe that an inac- 
curacy in figures resulted from the fact 
that waterfowl fed on seeds deposited 
prior to 1938 on mud flats that were 
bare in that year and that were therefore 
recorded as supporting no nutgrass 
plants. All evidence points to the fact 
that a somewhat similar situation oc- 
cured in 1939, when water prevented 
plants from appearing on many areas. 
In 1940, water levels were low earlier 
than in the 2 preceding years, so that by 
fall all mud flats were covered by a rank 
growth of vegetation. We believe that 
Fig. 5.—Nodding smartweed (Polygonum 
lapathifolium) grows on mud flats and other 
moist places. Its long, drooping, densely 
flowered spikes distinguish it from other smart- 
weeds. 
the index value as given in 1940 for this 
species is the most nearly accurate, 
table 6. This rating placed the nut- 
grasses above duck potato in value— the 
numerical value was over twice as great, 
