SUNFLOWER

Helianthus is a genus of plants comprising about 70 species. Except for three species in South America, all Helianthus species are native to North America and Central America. The common names "sunflower" and "common sunflower" typically refer to the popular annual species Helianthus annuus, whose round flower heads in combination with the ligules look like the sun. This and other species, notably Jerusalem artichoke (H. tuberosus), are cultivated in temperate regions and some tropical regions as food crops for humans, cattle, and poultry, and as ornamental plants. The species H. annuus typically grows during the summer and into early fall, with the peak growth season being mid-summer.

HISTORY OF SUNFLOWER

Perennial sunflower species are not as common in garden use due to their tendency to spread rapidly and become invasive. The whorled sunflower, Helianthus verticillatus, was listed as an endangered species in 2014 when the U.S. Fish and Wildlife Service issued a final rule protecting it under the Endangered Species Act. The primary threats are industrial forestry and pine plantations in Alabama, Georgia, and Tennessee. They grow to 1.8 m (6 ft) and are primarily found in woodlands, adjacent to creeks and moist, prairie-like areas.

This species was one of several plants cultivated by Native Americans in prehistoric North America as part of the Eastern Agricultural Complex. Although it was commonly accepted that the sunflower was first domesticated in what is now the southeastern US, roughly 5000 years ago, there is evidence that it was first domesticated in Mexico around 2600 BC. These crops were found in Tabasco, Mexico at the San Andres dig site. The earliest known examples in the United States of a fully domesticated sunflower have been found in Tennessee, and date to around 2300 BC. Other very early examples come from rock shelter sites in Eastern Kentucky. Many indigenous American peoples used the sunflower as the symbol of their solar deity, including the Aztecs and the Otomi of Mexico and the Incas in South America. In 1510 early Spanish explorers encountered the sunflower in the Americas and carried its seeds back to Europe. Of the four plants known to have been domesticated in eastern North America and to have become important agricultural commodities, the sunflower is currently the most economically important. During the 18th century, the use of sunflower oil became very popular in Russia, particularly with members of the Russian Orthodox Church, because sunflower oil was one of the few oils that was allowed during Lent, according to some fasting traditions. In the early 19th century it was first commercialized in the village of Alexeyevka in Voronezh Governorate by the merchant named Daniil Bokaryov, who developed a technology suitable for its large-scale extraction and quickly spread around. The town's coat of arms includes an image of a sunflower ever since. During the 19th century, it was believed that nearby plants of the species would protect a home from malaria. Among the Zuni people, the fresh or dried root is chewed by the medicine man before sucking venom from a snakebite and applying a poultice to the wound. This compound poultice of the root is applied with much ceremony to rattlesnake bites. Blossoms are also used ceremonially for anthropic worship.

  DISEASES of SUNFLOWER

Diseases of sunflowers include those caused by fungi, bacteria, viruses, and nematodes, fortunately, fewer than a dozen consistently cause serious economic damage worldwide. Most diseases commonly affecting sunflowers in this region are caused by fungi and are generally more severe in irrigated production.