Tansy ragwort-Senecio jacobaea L.-Poisonous plant

Tansy ragwort

General poisoning notes:

Tansy ragwort (Senecio jacobaea) is a naturalized herb that is found in fields in eastern Canada and British Columbia. This plant contains pyrrolizidine alkaloids which primarily cause irreversible liver cirrhosis in animals that ingest them. This plant has poisoned cattle and horses, and possibly goats. In the late 19th century and early 20th century, the mysterious Pictou cattle disease in Nova Scotia resulted in heavy losses of cattle. Tansy ragwort ingestion was recognized as causing the problem. In the 1960s cattle losses in Oregon valued at several million dollars were attributed to tansy ragwort ingestion. This plant should be eradicated from forage and crops (Cheeke and Schull 1985, Huxtable 1989). Animals and humans may be poisoned if they drink the milk of animals that have ingested this plant (Molyneux and James 1990, Bain 1990).

Description:

Perennials, 20–80(–100) cm (taprooted or branched caudices surmounting taproots). Herbage sparsely and unevenly tomentose, glabrescent except in leaf axils and among heads. Stems (often purplish-tinged) usually single, sometimes loosely clustered. Leaves ± evenly distributed (basal often withering before flowering); petiolate (sometimes obscurely); blades ovate to broadly ovate (usually 1–3-pinnate, lobes mostly obovate to spatulate), (4–)7–20(–30) × (1–)2–5(–12) cm, bases usually tapered, ultimate margins dentate (distal leaves similar, smaller). Heads (10–)20–60+ in corymbiform arrays. Calyculi of 2–6 (inconspicuous) bractlets (less than 2 mm). Phyllaries ± 13, 3–4(–5) mm, tips black or greenish. Ray florets ± 13; corolla laminae 8–12 mm. Cypselae all sparsely hairy or ray cypselae glabrous. 2n = 40.

Nomenclature:

Scientific Name: Senecio jacobaea L.

Synonyms: Jacobaea vulgaris Gaertn

Common names: erva-lanceta-do-Canadá (Portuguese-Brazil), jakobs-greiskraut (German), Jakobskruiskruid (Dutch), Landøyda (Norwegian), ragwort (English), séneçon Jacobée (Spanish), St. James'-wort (English), Starzec Jakubek (Polish), stinking willie  (English), tansy ragwort (English-USA)

Vernacular name(s): tansy ragwort

Scientific family name: Asteraceae.

Vernacular family name: composite

Habitat description:

Senecio jacobaea invades disturbed sites including roadsides, pastures and forest clearings (Macdonal & Russo, 1989). Records show that the distribution of the species is unlikely to be affected by extreme weather, although some cases have noted that a decrease in its population may be correlated with dry summers (Harper and Wood, 1957). Additionally, S. jacobaea distribution may be influenced by soil moisture, but not by soil acidity or texture (Sharrow et al, 1988).

Geographic Information

British Columbia, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec.

Notes on Poisonous plant parts:

All parts of the plant contain toxic pyrrolizidine alkaloids. The flowers contain the highest concentration of the toxins. The concentration in the leaves increases to a maximum just before flower maturity (Johnson and Molyneux 1986).

Toxic parts:

All parts, flowers, leaves, stems.

Notes on Toxic plant chemicals:

Pyrrolizidine alkaloids such as jacobine and seneciphylline are found in tansy ragwort. The content of these alkaloids has been measured at a mean of 0.31% (Cheeke and Schull 1985, Johnson and Molyneux 1986).

Toxic plant chemicals:

Jacobine, seneciphylline.

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:

abdominal edema

agitation

anorexia

diarrhea

jaundice

liver, cirrhosis of

nervousness.

Notes on poisoning:

So-called Pictou disease was identified in Pictou county, N. S., in cattle and horses; it also occurred in Prince Edward Island. For 20 years, the Canadian government ordered affected herds to be slaughtered before feeding trials confirmed, in 1906, that ingestion of tansy ragwort was responsible. The pyrrolizidine alkaloids cause irreversible liver cirrhosis, with pronounced fibrosis and biliary hyperplasia. Other symptoms include a peculiar bleached color of the hair, nervousness, incoordination, coma, and death. A rapid loss of milk production occurs in lactating cattle, and the milk may taste bitter with an unpleasant odor. Postmortem findings showed liver cirrhosis, often an enlarged gall bladder, abdominal edema, and edema in the mucosa and submucosa of the stomach and intestine (Pethick 1921, Cheeke and Schull 1985, Scimeca and Oehme 1985).

In a case in Oregon, a 3-week-old calf died. Post-mortem findings showed signs of liver cirrhosis; tansy ragwort poisoning was diagnosed. The dam did not show any signs of tansy ragwort poisoning. Milk from goats was also shown to pass the pyrrolizidine alkaloid (Pearson 1977).

Goats

General symptoms of poisoning:

abdominal edema

liver, cirrhosis of.

Notes on poisoning:

Goats are not usually poisoned, but if they are fed tansy ragwort they produce mutagenic milk. The pyrrolizidine alkaloids are found in the milk (Huxtable 1989).

Horses

General symptoms of poisoning:

abdominal edema

coma

death

depression

dyspnea

gait, staggering

incoordination

jaundice

liver, cirrhosis of

skin, peeling of

weight loss.

Humans

General symptoms of poisoning:

liver, cirrhosis of

Notes on poisoning:

Pyrrolizidine alkaloids from tansy ragwort were found in honey produced in Oregon and Washington states. The honey is off-color and bitter and is usually not sold. The amount of toxin is so low that acute symptoms of poisoning are unlikely. However, because the effects are cumulative, long term ingestion of this honey cannot be considered safe. There are no records of toxicity from ingesting honey (Fuller and McClintock 1986).