A tall, showy, yellow rosinweed with hairy stems. Blooms July through September. Flower heads are few to many, arising from a tall stalk. The flower heads are about 2½ inches across, and both the petal-like ray flowers and the central disk flowers are yellow. Leaves are hairy and deeply cleft almost to the midrib, the lobes sometimes having secondary divisions. At the bottom of the plant, the leaves are huge—to 16 inches long—but the leaves are progressively smaller toward the top of the stem. In full sun, the upright lower leaves turn their edges toward north and south, with the flat surfaces facing east and west, giving compass plant its common name.
Similar species: There are 6 Silphium species recorded for Missouri. The other most common ones are starry rosinweed, rosinweed, prairie dock, and cup plant. Compass plant is identified by its deeply cleft leaves.