Helenium autumnale

Common name: common sneezeweed

Helenium autumnale
Photo by the Atlas of Florida Plants Database
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta - Flowering plants
Class:	Magnoliopsida - Dicots
Order:	Asterales
Family:	Asteraceae
Genus:	Helenium
Species:	H. autumnale
Binomial name
Helenium autumnale L.
Natural range of Helenium autumnale from USDA NRCS Plants Database.

Taxonomic Notes

Synonyms: Helenium latifolium P. Miller, and Helenium parviflorum Nuttall; H. autumnale L. var. parviflorum (Nuttall) Fernald; H. autumnale L. var. autumnale

The genus name Helenium is thought to be named by Linnaeus after Helen of Troy, since the legend is that flowers of this genus sprung up where her tears fell.

Description

Also known as the common sneezeweed, H. autumnale is a native perennial forb that is a member of the Asteraceae family. It grows yellow conspicuous flowers and brown inconspicuous fruit. It has a winged stem with daisy-like flower heads and drooping fan-shaped ray flowers; disk flowers form a greenish-yellow and conspicuous ball-like structure located in the center of the head. Flowers have overall raised centers with yellow wedge-shaped petals that have three teeth each. In size classes 1 to 3 feet or 3 to 6 feet tall.

Distribution

H. autumnale can be found across the North American continent, from across the United States to most of Canada .

Ecology

Habitat

This species grows in a variety of communities, ranging from moist pastures to forests and woodlands. More specifically, habitats range from shady and loamy sand in mesic hardwoods floodplains, sandy alluvial dikes, drainage ditches, pine flatwood depressions, wet woodlands, wet roadsides, moist soil of limestone bluffs, and other moist sandy loams. It requires damp sites with moist clay soils usually, found in full sun in open areas along ponds and streams as well as wet meadows. It is listed by the USDA Natural Resources Conservation Service as a facultative wetland species that most often occurs in wetland habitats but also can occasionally be found in non-wetland habitats.

Associated species include Hyptis alata, Hyptis sp., Hydrolea sp., Pluchea sp., Solidago leavenworthii, Erianthus sp., Salix caroliniana, Acer rubrum, Eupatorium perfoliatum, Conoclinium coelestinum, Lythrum curtissii, Persicaria sp., Phanopyrum, Quercus virginiana, Quercus laurifolia, Liquidambar styraciflua, and others.

Phenology

Generally, H. autumnale flowers from September until October. It has been observed to flower in September , but has been seen to be flowering in the months of June through November. It has been seen to develop fruit in the months June through November as well.

Seed bank and germination

It was found to be a significant member of the seed bank at a tidal freshwater wetland and adjacent terrestrial areas along the Delaware River.

Fire ecology

It has been observed in habitats that are frequently burned.

Pollination

This species is thought by pollination ecologist to be of special value to native bees since it attracts such large numbers for pollination.

Use by animals

It is considered bitter and unpalatable to grazing animals which in turn makes it more abundant in pastures. The species consists of approximately 2-5% of the diet for various large mammals. This species attracts various butterflies. For humans, the flowers, leaves, and seeds are poisonous but only toxic if ingested in large quantities. Symptoms of this condition include elevated pulse and temperature, salivation, vomiting, difficulty breathing, and convulsions. The toxic principle of this plant is sesquiterpene lactone. It derives its common name from the former use of the dried leaves for making snuff, which was inhaled to cause sneezing which would apparently rid the body of evil spirits.

Conservation and Management

This species is critically imperiled in Vermont, and vulnerable in Massachusetts and the Canadian province Alberta. As well, it is considered to be weedy or invasive in Nebraska and the Great Plains region.