Autumn sneezeweed (Helenium autumnale)

Autumn sneezeweed photograph

Perennial to 4 feet tall. Single, leafy, winged stem. Flower heads 1 1/2 inches across, clustered at top of stem; yellow rays have lobed tips; disk is spherical or knoblike. Wet prairies and ditches. Reportedly toxic to livestock. Blooms July-August.