Characteristics: Common sunflower is an annual, warm-season forb native to North America. It can occasionally grow taller than 12 feet high in moist, nutrient-rich soils, but commonly reaches five to 10 feet tall. Widely branching, thick green stems are covered with stiff white hairs making it rough to the touch. Leaves can vary in shape from plant to plant, but leaves may also vary as a plant matures. New leaves are often lanceolate and become heart-shaped when mature. Leaves are also coarse like sandpaper as the upper and lower surfaces are covered in stiff hairs. The upper stems end in an inflorescence made up of many ray and disk flowers from July to August. Often mistaken as a single flower, this structure rotates to face the sun throughout the day.
Learn more about the common sunflower in the September issue of OKFR!