Comprehensive DescriptionRead full entry
CommentsBecause of its large size and long nodding seedheads, mature plants of Giant Foxtail (Setaria faberi) are quite conspicuous. It is one of several foxtail grasses (Setaria spp.) that are weedy summer annuals. Giant Foxtail is larger in size than most foxtail grasses that occur in Illinois, and its seedheads are long and conspicuously nodding. Most foxtail grasses in the state have seedheads that are straight or nod slightly. The bristly hairs of Giant Foxtail's seedheads are always green before they become light brown or straw-colored. In contrast, young bristly hairs of Yellow Foxtail's seedheads (Setaria glauca) are always yellow and those of Green Foxtail (Setaria viridis) are sometimes purple. Foxtail Millet (Setaria italica), in contrast, is very similar to Giant Foxtail in most of these characteristics, except it is somewhat larger in size. Foxtail Millet tends to have longer seedheads (up to 12" in length), longer culms (up to 6' in length), and wider leaf blades (up to 1¼" or 30 mm. across). While its seedheads often nod like those of Giant Foxtail, they are more stout in appearance because their lateral branches are longer. Sometimes, this provides them with a lumpy or lobed appearance that the seedheads of Giant Foxtail don't possess.