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.

References:

Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J., USA. 626 pp.

Nomenclature:

Scientific Name: Helenium flexuosum Raf.
 

Vernacular name(s): naked-flowered sneezeweed

Scientific family name: Compositae

Vernacular family name: composite

Go to ITIS*^ca for more taxonomic information on: Helenium flexuosum

References:

Agriculture Quebec. 1975. Noms des maladies des plantes du Canada/ Names of plant diseases in Canada. , Quebec City, Que., Canada. 288 pp.

Alex, J. F., Cayouette, R., Mulligan, G. A. 1980. Common and botanical names of weeds in Canada/Noms populaire et scientifiques des plantes nuisibles du Canada. Revised. Agric. Can. Publ., Ottawa, Ont., Canada. 132 pp.

Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.

Scoggan, H. J. 1978, 1979. The flora of Canada. Nat. Mus. Nat. Sci. (Ottawa) Publ. Bot. 7(1)-7(4). 1711 pp.

Van Wijk, H. L. 1911. A dictionary of plant names. Martinus Nijhoff, The Hague, The Netherlands. 1444 pp.

Victorin, M. 1964. Flore Laurentienne. 2nd ed. Univ. Montreal, Montreal, Que., Canada. 952 pp.

Geographic Information

Ontario
Quebec
 

References:

Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.

Boivin, B. 1966, 1967. Énumération des plantes du Canada. Provencheria 6. Nat. Can. (Que.) 93: 253-274; 371-437; 583-646; 989-1063. 94: 131-157; 471-528; 625-655.

Image or illustration

naked-flowered sneezeweed:

Images: images.google.com

Toxic parts:

leaves
stems
 

References:

Herz, W. 1978. Sesquiterpene lactones from livestock poisons. Pages 487-497 in Keeler, R. F., Van Kampen, K. R., James, L. F., eds. Effects of poisonous plants on livestock. Academic Press, New York, N.Y., USA. 600 pp.

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
 

References:

Herz, W. 1978. Sesquiterpene lactones from livestock poisons. Pages 487-497 in Keeler, R. F., Van Kampen, K. R., James, L. F., eds. Effects of poisonous plants on livestock. Academic Press, New York, N.Y., USA. 600 pp.

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).

References:

Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J., USA. 626 pp.