Cocklebur-Xanthium strumarium L.-Poisonous plant

Cocklebur

General poisoning notes:

Cocklebur (Xanthium strumarium) is a naturalized annual herb found across southern Canada, where it grows in wet soils and agricultural fields. The toxic glycoside carboxyatractyloside is found in the seeds and the cotyledons of seedlings. Livestock are most commonly poisoned after ingesting the cotyledons (seed leaves) of young seedlings. The toxin quickly dissipates as the seedlings grow. Cattle, horses, and swine are often poisoned and die after ingesting this plant. This plant can produce allergic contact dermatitis in susceptible humans (Mitchell and Rook 1979, Weaver and Lechowicz 1983, Burrows and Tyrl 1989).

Nomenclature:

Scientific Name: Xanthium strumarium L.

Vernacular name(s): cocklebur

Scientific family name: Compositae

Vernacular family name: composite

Geographic Information

Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince, Edward Island, Quebec, Saskatchewan

Notes on Poisonous plant parts:

The toxin is found in the seeds and in the cotyledons (or seed leaves) of the seedlings (Cole et al. 1980).

Toxic parts:

Seedlings, seeds

Notes on Toxic plant chemicals:

A highly toxic glycoside, carboxyatractyloside, is contained in the seeds and seedlings of cocklebur. The amount of the chemical was measured at 0.457% in the seeds and 0.12% in the seedling at the two-leaf stage. The poison occurs only in the cotyledons or seed leaves of the seedlings. The toxin readily disappears after germination (Cole et al. 1980).

Toxic plant chemicals:

carboxyatractyloside

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General symptoms of poisoning:

Anorexia, convulsions, death, depression, dyspnea, muscle, weakness of, nausea, opisthotonos.

Notes on poisoning:

Poisoning after ingesting cocklebur cotyledons from seedlings has resulted in symptoms including anorexia, depression, nausea, dyspnea, opisthotonos, and spasmodic running motions. Kidney discoloration and liver discoloration with acute hepatocellular centrilobular necrosis also occurs. Death often occurs, and treatment is symptomatic (Martin et al. 1986).

Humans

General symptoms of poisoning:

Erythema

Rodents

General symptoms of poisoning:

Death

Notes on poisoning:

Experimental use of carboxyatractyloside (CAT) in mice and rats, had an LD₅₀ (i.p. or injections into the peritoneal or abdominal cavity) of: ;10.6 (7.5-15.1) mg/kg for mice 2.9 (1.5-5.8)  mg/kg for rats; Postmortem examination revealed prominent hepatic lobular accentuation in rats (Cole et al. 1989).

Swine

General symptoms of poisoning:

Anorexia, death, depression, incoordination, muscle spasms, vomiting.

Notes on poisoning:

Pigs are poisoned after ingesting cotyledons equal to 1-2% of body weight or 20% of macerated burs containing seeds. Intoxication can occur within a few hours and symptoms include anorexia, depression, weakness, a tucked-up appearance, and spasmodic muscular activity. Postmortem findings reveal extensive serofibrinous effusions of protein- rich fluid in the peritoneal cavity. Scattered pericardial and subcutaneous lesions may also occur. Hepatic necrosis can occur (Burrows and Tyrl 1989).