yardgrass: coarse annual grass having fingerlike spikes of flowers; native to Old World tropics; a naturalized weed elsewhere
millet: any of various small-grained annual cereal and forage grasses of the genera Panicum, Echinochloa, Setaria, Sorghum, and Eleusine
prairie sunflower: similar to the common sunflower with slender usually branching stems common in central United States