About Helianthus argophyllus Torr. & A.Gray
Helianthus argophyllus Torr. & A.Gray, commonly called silverleaf sunflower, is a North American sunflower species. It is native to coastal regions of the U.S. state of Texas, and has become naturalized in other areas including Florida, North Carolina, Argentina, Africa, and Australia. This species is an annual herb that can grow up to 300 cm (10 feet) tall. Both its leaves and stems have a silvery appearance, caused by a dense coating of hairs covering their surfaces. A single plant can produce between 1 and 5 flower heads; each head holds 15 to 20 ray florets that surround 150 or more disc florets. This plant grows in sandy habitats near the seacoast.