The common sunflower, helianthus annuus
, is a familiar sight in fields and roadsides all across America. The large flowerheads can measure 5 inches across, with around 20 lightly grooved yellow ray florets surrounding a center of purplish-brown disc florets. The green phyllaries beneath the flower head are wide at the base but sharply pointed at the tip, and have a sparse covering of short hairs.
The plant branches readily and may produce many dozen flowers. Stems are thick, tough and hairy. Leaves grow on stalks; they are heart-shaped (cordate) around the base and ovate higher up. The disc florets develop into edible seeds in the fall.