Naked-flowered sneezeweed
General poisoning notes:
Naked-flowered sneezeweed (Helenium flexuosum) is a native herb found in Ontario and Quebec. This plant has caused poisoning in horses and sheep and, experimentally, in calves. It contains sesquiterpene lactones.
Nomenclature:
Scientific Name: Helenium flexuosum Raf.
Vernacular name(s): naked-flowered sneezeweed
Scientific family name: Asteraceae
Vernacular family name: asteraceae
Helenium flexuosum Raf.
Geographic Information
Ontario, Quebec.
Toxic parts:
Leaves, stems.
Notes on Toxic plant chemicals:
Flexuosin A and B are closely related to the chemical helenalin, which is found in sneezeweed (Helenium autumnale). These are all sesquiterpene lactones (Herz 1988).
Toxic plant chemicals:
Flexuosin A, flexuosin B
Flexuosin B
Animals/Human Poisoning:
Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.
Cattle
Horses
Sheep
General symptoms of poisoning:
Convulsions, dyspnea, weakness.
Notes on poisoning:
Horses are more susceptible than sheep to poisoning by naked-flowered sneezeweed (Kingsbury 1964).
