Sneezeweed
Sneezeweed, the common name of a genus of annual and perennial herbs. There are about 40 species, native to North and South America. They usually grow wild in moist areas such as meadows and along river banks. Some species are cultivated as garden plants. Sneezeweeds are usually from about one to six feet (30–180 cm) in height. Atop the plant's stems are clusters of yellow or orange (depending on species) flower heads. The flower heads are similar to daisies in appearance. Their odor is supposed to cause sneezing. Many species of sneezeweed are poisonous to livestock. Cattle and sheep grazing upon these plants are often affected with “spewing sickness” in which there is chronic vomiting and sometimes convulsions and death.
The common sneezeweed is found throughout eastern North America from southern Canada to Florida. It grows from about two to six feet (60–180 cm) in height. Each of its flower heads is about two inches (5 cm) in diameter and is made up of dark yellow disc flowers surrounded by lighter yellow ray flowers.
Sneezeweeds make up the genus Helenium of the composite family, Compositae. The common sneezeweed is H. autumnale.