Heliopsis helianthoides, known by the common names rough oxeye, smooth oxeye, and false sunflower, is native to eastern and central North America. Flowering midsummer to early fall, it produces bright yellow flowers about 3″ in diameter. Plants are tall (up to five feet) and stiff, so staking may be advisable for the tallest of them. It grows in moist, fertile soil with, as the name suggests, full sun. It does not spread by rhizomes, but will self-sow readily.