Bog-laurel-Kalmia polifolia Wang-Poisonous plant

Bog-laurel

General poisoning notes:

Bog-laurel (Kalmia polifolia) is a native shrub found across Canada in boggy areas. The plant has caused experimental poisoning in cattle, goats, and sheep, with sheep being most susceptible. Suspected poisoning of cattle and sheep in the west have been reported. Bog-laurel is less toxic than sheep-laurel (Kalmia angustifolia). Only the western variety of bog-laurel (Kalmia polifolia var. microphylla) has been tested for toxicity. However, the plant should be considered potentially toxic through its entire range in Canada (Clawson 1933, Kingsbury 1964, Lampe and McCann 1985).

Nomenclature:

Scientific Name: Kalmia polifolia Wang

Vernacular name(s): bog-laurel

Scientific family name: Ericaceae

Vernacular family name: heath

Geographic Information

Alberta, British Columbia, Labrador, Manitoba, New Brunswick, Newfoundland,, Northwest Territories, Nova Scotia, Ontario, Prince Edward Island, Quebec,, Saskatchewan, Yukon Territory

Notes on Poisonous plant parts:

All parts of the plant are poisonous including the nectar, which can result in poisonous honey. The leaves have been used in experiments to poison livestock (Clawson 1933, Fuller and McClintock 1986).

Toxic parts:

All parts, leaves, stems

Notes on Toxic plant chemicals:

Andromedotoxins (grayanotoxins) are resins derived from diterpenes. Several have been found in many members of the heath family and are toxic if sufficient vegetation is eaten (Kakisawa et al. 1965, Fuller and McClintock 1986).

Toxic plant chemicals:

Andromedotoxins

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

Goats

General symptoms of poisoning:

Depression, nausea, salivation, vomiting

Notes on poisoning:

Experimental poisoning of sheep caused such symptoms as depression, salivation, loss of appetite, and vomiting. Grating of teeth and frequent vomiting was noticed in more severe cases. Pulse and body temperature was affected very little. A dosage of green leaves equal to 0.3% of an animal''s body weight can cause a toxic response. A dosage of 2% of an animal''s body weight caused severe sickness in sheep (Clawson 1933).

Sheep

General symptoms of poisoning:

Depression, gait, staggering, nausea, recumbency, salivation, vomiting

Notes on poisoning:

Experimental poisoning of sheep caused such symptoms as depression, salivation, loss of appetite, and vomiting. Grating of teeth and frequent vomiting was noticed in more severe cases. Pulse and body temperature was affected very little. A dosage of green leaves equal to 0.3% of an animal''s body weight can cause a toxic response. A dosage of 2% of an animal''s body weight caused severe sickness in sheep (Clawson 1933).