Common Sunflower

(Helianthus annuus)

Adopted in 1903.

The Kansas state flower is the the helianthus or wild native sunflower, Helianthus annuus. It was adopted as the  the state flower and floral emblem in 1903.

There are eleven species of sunflower recorded from Kansas. Most of them are perennials.

In September the fields and roadsides of the Great Plains erupt in a blaze of yellow as the sunflowers and goldenrods (also members of the sunflower family) make their presence known to the local pollinating insects. While many sunflower species may begin blooming in July, they are not as noticeable then as later on when they have grown up and over the surrounding vegetation. There are eleven species of sunflower recorded from Kansas. Most of them are perennials. Only the common sunflower and H. petiolaris, the Prairie Sunflower, are annuals. Identification of sunflowers can be very complicated because they frequently hybridize and even within species there is a high degree of variability. With a little practice, however, the most common species can be readily recognized.

The Common Sunflower has a long history of association with people. Nearly 3,000 years ago it was domesticated for food production by the Native Americans. The seeds of the wild type of sunflower are only about 5 mm. long. It was only through careful selection for the largest size seeds over hundreds of years that the cultivated sunflower was produced. Lewis and Clark made mention in their journals of its usage by the plains Indians. It was brought back to the Old World by the early European explorers and widely cultivated there also. Today it is a common alternative crop in the Great Plains and elsewhere for food and oil production. Next time you munch down on some sunflower seeds, thank the many generations of Native Americans whose careful husbandry gave us this valuable food item.

The wild cousins of those grown on the farm are still common, however, in fields, roadsides and disturbed ground throughout the Great Plains.

The Common Sunflower is a typical member of the Asteraceae, one of the largest and most successful families of plants. Within the structure we think of as the "flower", it actually has two different types of flowers - ray and disk flowers.

The ray flowers have the big, straplike structures that we see around the edge of the "flower" while the disk flowers occupy the middle of it. Within the Asteraceae, many confusing combinations of the two are possible along with the total absence of one or the other in some species! Individual ray or disk flowers may be male, female or both and either fertile or infertile (do or don't produce seeds). In sunflowers, the ray flowers are usually female and infertile. The disk flowers are both male and female and are fertile.

If you look closely at the center of a sunflower you can see that the disk flowers grow in a mesmerizing pattern of two opposite spirals. This is most easily seen either before the disk flowers open up or after the seed has set and all the accessory flower parts have fallen off. This is one of the more interesting patterns in nature.

The rough-hairy quality of the Common Sunflower is characteristic of many members of its family. These little bristles probably serve two functions: to discourage plant-eating animals and to conserve water in the plant by limiting evaporation.

Members of the sunflower family are popular with butterflies because the wide flower head makes a good "landing platform" and the numerous individual flowers make for a high probability of finding nectar. Monarch butterflies are commonly seen nectaring on sunflowers during their fall migration.

Whether as a source of food for people and wildlife or an eye-catching splash of color on the landscape, the Common Sunflower is an important member of the prairie community.

• Flowering Season: Summer
• Light Requirements: Sun
• Flower Color: Gold, red-brown, yellow
• Height: 12 to 108 inches
• Spacing: 12 to 24 inches
• Comments: Moderate to high drought tolerance
• Cultivars: Full Sun Single