. Bulletin. Natural history; Natural history. May, 1943 Bellrose & Anderson: Duck Food Plants 423 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 tha
. Bulletin. Natural history; Natural history. May, 1943 Bellrose & Anderson: Duck Food Plants 423 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 rating derived from data obtained in all 3 years places this group, Cyperus ery- throrhizos^ C. strigosus and C. esculcntus, 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. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Il
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