Sunflower the State Flower of Kansas
The Sunflower is the state flower of Kansas.
Sunflower the State Flower of Kansas
Sunflowers make great garden plants. The are very pretty and people and birds can eat the seeds. Sunflowers are often used in fall floral arrangements.
Read more about Sunflower the State Flower of Kansas.
The sunflower (Helianthus annuus) is an annual plant in the family Asteraceae, with a large flower head (inflorescence). The stem of the sunflower can grow up to 9 feet tall, with the flower head reaching over 11 inches in diameter. The term "sunflower" is also used to refer to all plants of the genus Helianthus, many of which are perennial plants.
Heliotropism in Sunflowers
Most flowerheads on a field of blooming sunflowers are turned towards the east, where the sun rises each morning. Immature sunflowers in the bud stage exhibit heliotropism and on sunny days track the sun on its journey along the sky from east to west, while at night or at dawn they return to its eastward orientation.
Notice almost all the sunflowers on this farm are facing the sun.
The motion is performed by motor cells in the pulvinus, a flexible segment of the stem just below the bud. The stem stiffens at the end of the bud stage, and when the blooming stage is reached the stem freezes in its eastward direction. Thus, blooming sunflowers are not heliotropic anymore, even though most flowerheads are facing the direction where the sun rises.
The inflorescence of the wild sunflower seen on roadsides does not turn toward the sun. In this sunflower, the flowering heads face many directions when mature. But the leaves exhibit some heliotropism.
Garden cultivation and uses of the sunflower
Sunflowers are native to the Americas, and were domesticated around 1000 B.C. Francisco Pizarro found the Inca subjects venerating the sunflower as an image of their sun god. Gold images of the flower, as well as seeds, were taken back to Europe early in the 16th century. Helianthus is the Greek word for "sunflower".
To grow well, sunflowers need full sun. They grow best in fertile, moist, well-drained soil with a lot of mulch. In commercial planting, seeds are planted 45 cm (1.5') apart and 2.5 cm (1") deep.
Sunflower "whole seed" (fruit) is sold as snacks, especially in China, the United States and Europe. It is also sold as food for birds and can be used directly in cooking and salads.
Sunflower oil, extracted from the seeds, is used for cooking (but is less cardiohealthy than olive oil), as a carrier oil and to produce biodiesel, for which it is less expensive than the olive product.
The cake remaining after the seeds have been processed for oil is used as a livestock feed. Some recently developed cultivars have drooping heads. These cultivars are less attractive to gardeners growing the flowers as ornamental plants, but appeal to farmers, because they reduce bird damage and losses from some plant diseases. There are also new breeds of sunflowers which are transgenic, so that they are resistant to some diseases. Sunflowers also produce latex and are the subject of experiments to improve their suitability as an alternative crop for producing hypoallergenic rubber. Additionally, the stem of a dead sunflower can dry out open wounds.
For farmers not intending to grow it, the sunflower is considered a noxious weed. The wild variety will grow unwanted in corn and soy bean fields which can have a negative impact on yields.
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