Yellow Toadflax (Common name)

General poisoning notes:

Yellow toadflax (Linaria vulgaris) is an introduced herb that is widely naturalized across Canada. This plant contains several compounds, including glucosides and the cyanogenic glucoside prunasin. The plant is regarded as toxic to livestock in Europe. Cattle generally avoid grazing stands of this plant, but there is more potential for poisoning when the animals are provided with hay that has a high content of yellow toadflax. No definitive records of poisoning are found in the literature. Other members of the genus are found in Canada as well, including the introduced Dalmatian toadflax (Linaria dalmatica). For safety's sake, hay should not be fed to livestock if it contains a high content of these plants.

References:

  • Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J., USA. 626 pp.
  • Sticher, O. 1971. Isolation of antirrinoside from Linaria vulgaris. Phytochemistry (Oxf.), 10: 1974-1975.

Nomenclature:

Scientific Name:
Linaria vulgaris Mill.
Vernacular name(s):
yellow toadflax
Scientific family name:
Scrophulariaceae
Vernacular family name:
figwort

Go to ITIS*ca for more taxonomic information on: Linaria vulgaris

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

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

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

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Toxic parts:

  • leaves

References:

  • Sticher, O. 1971. Isolation of antirrinoside from Linaria vulgaris. Phytochemistry (Oxf.), 10: 1974-1975.

Notes on Toxic plant chemicals:

Yellow toadflax contains several chemicals, including the cyanogenic glycoside prunasin. It also contains a glucoside, antirrinoside (Sticher 1974; Conn 1981).

Toxic plant chemicals:

  • antirrinoside
  • prunasin

References:

  • Conn, E. E. 1981. Cyanogenic glycosides. Pages 479-501 in Stumpf, P. K., Conn, E. E., eds. The biochemistry of plants. Vol. 7. Secondary plant products. Academic Press, New York, N.Y., USA. 600 pp.
  • Sticher, O. 1971. Isolation of antirrinoside from Linaria vulgaris. Phytochemistry (Oxf.), 10: 1974-1975.

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:

Notes on poisoning:

General symptoms of cyanide poisoning are listed above. These symptoms have not been reported in the literature for ingestion of yellow toadflax. The general symptoms for cyanide poisoning were taken from 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.

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