The Sunflower (Helianthus annuus) is a fast-growing annual herbaceous plant in the Asteraceae family. It’s easily recognized by its tall, sturdy stem—which can reach 2 to 3 meters in height—and its large, bright yellow flower heads. These are actually inflorescences made up of outer ray florets and central disc florets. Young sunflowers are known for heliotropism, the movement of the flower heads following the sun throughout the day. Sunflowers are cultivated both for ornamental purposes and for seed and oil production.