General poisoning notes:

Colorado rubberweed (Hymenoxys richardsonii) is a native herb found in the southern prairies. This plant has caused poisoning and death in sheep, goats, and occasionally cattle. Sheep and goats consume this plant when there is little else to eat. Poisoning is therefore most frequent in spring and late autumn, when other forage is reduced. Cattle are poisoned less frequently because they find the plant unpalatable (Cheeke and Schull 1985).

References:

Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Parker, K. W. 1936. Prevention of death losses in sheep on areas infested with pingue (Actinea richardsoni). N. M. Agric. Exp. Stn. Bull., 241. 53 pp.

Nomenclature:

Scientific Name: Hymenoxys richardsonii (Hook.) Cockerell

Vernacular name(s): Colorado rubberweed

Scientific family name: Compositae

Vernacular family name: composite

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
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.

Toxic parts:

all parts
leaves
stems

References:

Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Notes on Toxic plant chemicals:

Hymenovin (hymenoxon) is a sesquiterpene lactone that contains an alpha-methylene-gamma-lactone moiety. This moiety inhibits the enzymatic capability of adenylate cyclase by alkylation of its thiol group. The inhibition can disrupt the cellular transmission of external signals to the internal regulatory proteins. Mercaptans, such as cysteine, may be used in treatment by partly detoxifying the moiety before it can damage cellular enzymes (Elissalde and Ivie 1987). The oral LD-50 of hymenovin (hymenoxon) is 2.9-8.5 g/kg in sheep (Cheeke and Schull 1985).

Toxic plant chemicals:

hymenovin

References:

Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Elissalde, M. H., Ivie, G. W. 1987. Inhibition of macrophage adenylate cyclase by the alpha-methylene-gamma-lactone moiety of sesquiterpene lactones from forage plants. Am. J. Vet. Res., 48: 148-152.

Animals/Human Poisoning:

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

Cattle

Goats

Sheep

General symptoms of poisoning:

death
kidney, congestion of
liver, congestion of
lungs, congestion of
vomiting

Notes on poisoning:

Symptoms of ingestion include violent vomiting, hence the name spewing sickness. Sheep may have a green stain around the mouth. Vomited material can be inhaled, which can lead to inhalation pneumonia, permanent lung damage, or death. Lesions in the gastrointestinal tract, liver and kidney congestion, and lung damage occur. Frequent coughing and sneezing occur (Parker, Cheeke and Schull 1985).

References:

Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Parker, K. W. 1936. Prevention of death losses in sheep on areas infested with pingue (Actinea richardsoni). N. M. Agric. Exp. Stn. Bull., 241. 53 pp.

Information Source: ©Canadian Poisonous Plants Information System, Canadian Biodiversity Information Facility.