Purple locoweed-Oxytropis lambertii Pursh

Purple locoweed

General poisoning notes:

Purple locoweed (Oxytropis lambertii) is found in the southern parts of Manitoba and Saskatchewan. This species can cause locoism, a chronic disease that results after long-term grazing. The plant contains swainsonine, an alkaloid, which results in cellular dysfunction through a long biological process. Affected animals show nervous system impairment, with symptoms such as dullness and excitement, as well as immune system impairment. Abortion and congenital birth deformities may occur. Animals affected include cattle, horses, and sheep. Animals may become habituated to locoweed. Death can result (James 1983, Cheeke and Schull 1985).

Nomenclature:

Scientific Name: Oxytropis lambertii Pursh

Vernacular name(s): purple locoweed

Scientific family name: Leguminosae

Vernacular family name: pea  

Oxytropis lambertii Pursh

Geographic Information

Manitoba, Saskatchewan.

Notes on Poisonous plant parts:

The blooms of locoweeds contain more swainsonine than the leaves. The immature pods contain less swainsonine than the blooms, but this amount increases with the maturity of the seeds (Ralphs et al. 1986).

Toxic parts:

Flowers, leaves, mature fruit.

Notes on Toxic plant chemicals:

Swainsonine, an indolizidine alkaloid, inhibits alpha-mannosidase in the animal''s body, which results in eventual disruption of cellular function when inhibited (Cheeke and Schull 1985).

Toxic plant chemicals:

Swainsonine

Swainsonine

Chemical diagram(s) are courtesy of Ruth McDiarmid, Biochemistry Technician, Kamloops Range Station, Agriculture and Agri-Food Canada, Kamploops, British Columbia, Canada.

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:

Abortion, agitation, carpal joint, flexure, death, depression.

Horses

General symptoms of poisoning:

Agitation, death, depression.

Sheep

General symptoms of poisoning:

Abortion, agitation, carpal joint, flexure, death, incoordination.