. Bulletin. Natural history; Natural history. 424 Illinois Natural History Survey Bulletin Vol. 22. Art. 5 in fact—but below the group consisting principally of notiding, large-seed and swamp smartweed. The relative value of the three species of nutgrasses may be judged by the fol- lowing facts: Cy perns erythrorhizos^ represented by per cent of the total nutgrass seed found in duck gizzards, was much more abundant than C. stri- gosus, represented by per cent of the nutgrass seed; C. csciilcHlus, how- ever, made up per cent of the total nutgrass seed, even though less abun- dant
. Bulletin. Natural history; Natural history. 424 Illinois Natural History Survey Bulletin Vol. 22. Art. 5 in fact—but below the group consisting principally of notiding, large-seed and swamp smartweed. The relative value of the three species of nutgrasses may be judged by the fol- lowing facts: Cy perns erythrorhizos^ represented by per cent of the total nutgrass seed found in duck gizzards, was much more abundant than C. stri- gosus, represented by per cent of the nutgrass seed; C. csciilcHlus, how- ever, made up per cent of the total nutgrass seed, even though less abun- dant than C. s/rigosus. This would in- dicate that C. esculent us was slightly better than C. erylh-orhizos, which, in turn, was better than C. strigosus. Moist-soil smartweeds, consisting of largeseed smartweed, Polygonum pennsylvanicum, fig. 4, nodding smart- weed, P. lapathifolium, fig. 5, swamp smartweed, P. hydropiperoides^ and minor quantities of other species, rank fourth for the 3-year period, table 3. However, here also the same factors prevail that were responsible for an error in the index value of the nut- grasses: in many places seeds deposited. M Fig. 6.—Japanese millet {Echinochloa frii- mentacea) under favorable growing conditions is one of the greatest seed producers among the duck food plants of the Illinois River valley. Because its seed production is greatly depend- ent on growing conditions, its comparative value ranges from excellent to fair in the course of several years. in one year were consumed the next, when germination did not occur and plants were not recorded. The 1940 index rating of in table 6 is probably the most nearly accurate. It places these species slightly above the nut- grasses in value. Wild and Japanese millets, Echi- nochloa crusgalli and frumentacea^ fig. 6, appear fifth in order of preference in table 3, covering 1938, 1939 and 1940. For some reason, waterfowl did not ob-. Please note that these images are extracted from sca
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