Naked-flowered sneezeweed-Poisonous plant

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

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

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).