Rhus diversiloba (Scientific name)

General poisoning notes:

Western poison-oak (Rhus diversiloba; synonym Toxicodendron diversiloba) is a native shrub found in southwestern British Columbia. This plant contains urushiol, which is highly sensitizing in humans. Reactions can range from mild redness to large areas of oozing lesions and fever (Mulligan 1990, Gayer and Burnett 1988).

References:

  • Epstein, W. L., Byers, V. S. 1981. Poison oak and poison ivy dermatitis. Prevention and treatment in forest service work. U.S. Dep. Agric. For. Serv. Rep., 14 pp.
  • Gayer, K. D., Burnett, J. W. 1988. Toxicodendron dermatitis. Cutis, 42: 99-100.
  • Mulligan, G. A. 1990. Poison ivy. Western poison oak. Poison sumac. Agric. Can. Publ., 1699. 13 pp.

Nomenclature:

Scientific Name:
Rhus diversiloba T. & G.
Vernacular name(s):
western poison-oak
Scientific family name:
Anacardiaceae
Vernacular family name:
cashew

Go to ITIS*ca for more taxonomic information on: Rhus diversiloba

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

  • British Columbia

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

Images: Rhus diversiloba - Google Search

Notes on Poisonous plant parts:

All parts of the plant, with the exception of the pollen, anthers, xylem, and epidermis, contain the allergen urushiol. Even in winter, sap from damaged stems causes allergic reactions. Similarly, damage to the root results in dermatitis (Mulligan 1990, Gayer and Burnett 1988).

Toxic parts:

  • all parts
  • flowers
  • immature fruit
  • leaves
  • mature fruit
  • plant juices
  • stems

References:

  • Epstein, W. L., Byers, V. S. 1981. Poison oak and poison ivy dermatitis. Prevention and treatment in forest service work. U.S. Dep. Agric. For. Serv. Rep., 14 pp.
  • Gayer, K. D., Burnett, J. W. 1988. Toxicodendron dermatitis. Cutis, 42: 99-100.
  • Mulligan, G. A. 1990. Poison ivy. Western poison oak. Poison sumac. Agric. Can. Publ., 1699. 13 pp.

Notes on Toxic plant chemicals:

Urushiol, a nonvolatile phenolic allergen, includes alkylcatechols, found in all toxic Rhus species. Urushiol is found in the resin canals that occur throughout the plants. The toxin is exposed after damage to the plant (Gayer and Burnett 1988).

Toxic plant chemicals:

  • urushiol oil

References:

  • Epstein, W. L., Byers, V. S. 1981. Poison oak and poison ivy dermatitis. Prevention and treatment in forest service work. U.S. Dep. Agric. For. Serv. Rep., 14 pp.
  • Gayer, K. D., Burnett, J. W. 1988. Toxicodendron dermatitis. Cutis, 42: 99-100.
  • Schmidt, R. J., Khan, L., Chung, L. Y. 1990. Are free radicals and not quinones the haptenic species derived from urushiols and other contact allergenic mono-and dihydride alkylbenzenes? Dermatol. Res., 282: 56-64.

Animals/Human Poisoning:

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

Humans

General symptoms of poisoning:

References:

  • Epstein, W. L., Byers, V. S. 1981. Poison oak and poison ivy dermatitis. Prevention and treatment in forest service work. U.S. Dep. Agric. For. Serv. Rep., 14 pp.
  • Mulligan, G. A. 1990. Poison ivy. Western poison oak. Poison sumac. Agric. Can. Publ., 1699. 13 pp.

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