What plant is that?

This attractive opposite-leaved herb of moist thickets and shorelines grows to 1-3 feet tall and has large yellow flowers in summer. The leaves are entire and ovate (egg-shaped) while the petioles (leaf stalks) have long hairs their entire length. The flowers arise on long pedicels from the leaf axils and have five petals that are nearly round and toothed at the tip.