Plant of the Week

Common sneezeweed (Helenium autumnale L. var. autumnale)

By Sue Trull, Ottawa National Forest

Common sneezeweed is a perennial plant in the daisy or aster family (Asteraceae). Its abundant yellow blooms can be found in late summer to fall, often attracting bees and butterflies. Common sneezeweed can be found in much of the United States, in moist to wet openings, edges, shores, and thickets.

Like other members of the aster family, the 1-2 inch sneezeweed flower is composite—with large, showy ray flowers that look like petals, and smaller disk flowers making up the center. The bright yellow "petals" are wedge-shaped, with three lobes on the outer end, drooping away from the central disk. The center is nearly spherical, projecting above the skirt-like whorl of petals. The center disk flowers are a duller yellow color than the petals. The plant's stem branches near the top, resulting in many flowers on each plant.

Sneezeweed leaves are lance-shaped to narrowly oval, with a few teeth. These leaves occur alternately on the stem. They are directly attached, with the leaf base continuing down the stem as a wing. Sneezeweed stems can be slightly hairy and they can reach five feet or more in height.

Sneezeweed can be cultivated in average to rich soils, needing moist to wet conditions and full sun. The plants often become so tall they need staking or other support. Alternatively, they can be cut back in early summer (that is, late June or early July) to force shorter, more-branched flowering heads. Flowering clumps can be divided every few years to maintain vigor and provide new plant starts for other areas. Seeds can be collected for starting new plants as well, although germination rates can be quite low.

Common sneezeweed is also known as Helen's flower, bitterweed, autumn sneezeweed, and false sunflower. The genus name, Helenium, refers to the famous Helen of Troy. There is a legend that these flowers sprang from the ground where Helen's tears fell. The species name, autumnale, refers to the season of the flower's blooming—autumn. Synonyms for the scientific name include Helenium canaliculatum, H. latifolium, and H. parviflorum.

According to a 1923 publication by H. Smith of the Milwaukee Public Museum, the name given to the plant by the Menominee Indians of the Wisconsin area is "aiatci'a ni'tcîkûn," which means "sneezing spasmodically". With its large showy flowers, insects pollinate common sneezeweed, not wind. Therefore, it does not have small pollen grains, like ragweed does, which cause sneezing and other hay fever symptoms. This is not the reason for the Menominee and English names for the plant. The common name is based on historic use of the crushed dried leaves and heads to make a form of snuff that caused sneezing. In certain cultures and times, sneezing was regarded as a desirable way to rid the body of evil spirits or a way to loosen up a head cold, so that a sneeze-producing remedy was desirable. Having crushed dried sneezeweed heads to collect the seeds, the author can attest to the plant's sneeze-producing power!

Common sneezeweed leaves, flowers, and seeds are poisonous to humans, if eaten in large quantities, causing gastric and intestinal irritation, which can become fatal. The plants also contain sesquiterpene lactones, which may cause a skin rash in some people. The chemicals in sneezeweed can poison livestock, particularly sheep. The sesquiterpene lactone helenalin found in sneezeweed also has been found to be poisonous to fish and dogs. It is a crystalline substance with the chemical formula C₂₀H₂₅O₅, which irritates mucous membranes. Sesquiterpene lactone chemicals are common in Aster family plants, and may help protect the plants from pathogens and herbivores.

For More Information

• PLANTS Profile - Helenium autumnale var. autumnale, common sneezeweed