Common Sunflower

Family: 
Asteraceae (daisies)
Description: 

Extremely variable in height and appearance, but grows easily to 7 feet tall, with hairy stems. Blooms July through November. Flowerheads of wild form are many per plant, with brown disks, and frequently with a double set of ray florets, commonly yellow. Large, with disk usually a couple inches in diameter not including the rays. Cultivated forms can be much larger, often with only one flowerhead per plant. Leaves are large, ovate to broad, with irregular, large teeth, mostly alternate except the uppermost ones. Lower leaves are usually heart-shaped. All leaves are rough and hairy.

Size: 
Height: usually to 7 feet in wild forms.
Habitat and conservation: 
Grows scattered in wasteland along roadsides as well as in cultivation. It is not known for sure if this species is truly native to Missouri, since American Indians domesticated and distributed the plant early, and European settlers also spread the plant around. The species was brought to Europe as early as the 1500s. The most famous domesticated common sunflower, the unbranched, large-headed ‘Mammoth Russian’ type, was developed in Russia, then brought to America.
Distribution in Missouri: 
Statewide, scattered. Mostly absent from the Ozarks and Mississippi Lowlands.
Status: 
Scattered and common. An immensely important crop plant historically and today, and also beloved by painters, photographers, poets, and novelists. To learn more, seek out the seminal writings of ethnobotanist and enthusiastic sunflower specialist Charles B. Heiser.
Human connections: 
This species is the most important crop plant that is native to the United States. It is cultivated worldwide for sunflower oil, made from the seeds. The plant is also an ornamental and provides food for livestock and wildlife. At one time Missouri was a leading producer of sunflowers.
Ecosystem connections: 
Wildlife eat the seeds, which are rich in oil and proteins, as well as the foliage. Because they grow readily on open or disturbed ground, sunflowers help bind the soil. There are about 16 different species of Helianthus sunflowers in Missouri, and all serve the natural world in these ways.