is a tall plant, producing rigid, upright, branched stems and large green, toothed leaves, triangular to lanceolate in outline. Leaves are opposite on the stem, alternate around the base. Leaf surfaces are somewhat rough due to a covering of short hairs. Flowerheads are up to 2 inches across, formed of 8 to 15 or more (usually around 12) broad yellow ray petals that have two lengthwise grooves leading to notches at the tip. The flower center contains around 80 to 150 tubular yellow disc florets. Phyllaries typically number 15; they are linear in shape, and curve outwards. Flowers are usually single. This species grows on open land and spreads rapidly, often to the detriment of other plants in the area.