February daphne-Daphne mezereum L.-Poisonous plant

February daphne

General poisoning notes:

February daphne (Daphne mezereum) is an ornamental shrub that grows across southern Canada. This shrub and other Daphne species are poisonous to humans and animals. The plants contain irritant chemicals that cause pain, burning, and tingling sensations on exposed skin. These sensations are intensified on mucous membranes in the mouth, throat, and stomach after ingesting the fruits. More serious symptoms also occur in humans, including kidney damage, which may lead to death. With the exception of February daphne, the other Daphne species and cultivars are found only as ornamental plants in the more southerly and temperate parts of Canada. February daphne is naturalized in several eastern provinces. Horses and swine have been poisoned and have died after ingesting daphne leaves or berries, although poisoning of animals is a rare occurrence. Family pets can be poisoned if they have access to the plants. Several references give additional information (Frohne and Pfander 1983, Cooper and Johnson 1984, Lampe and McCann 1985, Fuller and McClintock 1986).

Nomenclature:

Scientific Name: Daphne mezereum L.

Vernacular name(s): February daphne

Scientific family name: Thymelaeaceae

Vernacular family name: mezereum  

Geographic Information

Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec.

Notes on Poisonous plant parts:

All the Daphne species in this information system have the same toxic chemical found in all parts of the plant. The only part of the plants without mezerein is the fruit pulp. It is the broken seeds that are responsible for symptoms when fruit is chewed. Ingesting one or two of the bitter berries can cause severe poisoning in children. Twelve berries can be fatal to an adult human (Frohne and Pfander 1983, Fuller and McClintock 1986).

Toxic parts:

All parts, bark, flowers, mature fruit, seeds.

Notes on Toxic plant chemicals:

Daphnetoxin and mezerein are diterpene alcohols with a daphnane skeleton. Mezerein has cocarcinogenic activity as does the chemically related phorbol esters found in many toxic members of the spurge family (Euphorbiaceae). In mice, daphnetoxin was determined to have an LD₅₀ of 275 micro g/kg and the mouse ear inflammation unit is 0.2 micro g of mezerein per ear (Frohne and Pfander 1983). The bark of these daphne plants contains a coumarin glycoside that has the aglycone dihydroxycoumarin (Fuller and McClintock 1986).

Toxic plant chemicals:

Daphnetoxin, dihydroxycoumarin, mezerein.

Animals/Human Poisoning:

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

Dogs

Horses

General symptoms of poisoning:

Abdominal pains, death, vomiting.

Notes on poisoning:

Horses have been poisoned by the leaves and berries of the Daphne species. Abdominal pains, breathing problems, and death occurred. Post- mortem symptoms included inflammation, swelling, and blood-stained contents of the gastrointestinal tract. Experimental feeding produced similar symptoms but did not result in death. Only 100-150 g of the plants, which are bitter, were eaten (Cooper and Johnson 1984).

Humans

General symptoms of poisoning:

Abdominal pains, breathing, labored, convulsions, death, diarrhea, dysphagia, gait, staggering, hoarseness, kidney failure, mouth, irritation of, muscle twitching, prostration, temperature, elevated, thirsty, vomiting.

Notes on poisoning:

Human poisoning by the Daphne species can include minor irritation of the mouth region including pain, burning, and tingling. If the plant material is also chewed and ingested, more severe symptoms occur, including bloody diarrhea, abdominal pains, vomiting, and convulsions. In severe cases, prostration, hallucinations, shedding of the lining of the oral and mucous membranes, and renal damage can occur. In one case, a child was killed in Nova Scotia after ingesting berries (Fyles 1920). Ingestion may lead to muscular twitching and somnolence, which persists for days. Few cases of poisoning actually occur, but the consequences of ingestion can be serious (Frohne and Pfander 1983, Cooper and Johnson 1984, Lampe and McCann 1985, Fuller and McClintock 1985).

Swine

General symptoms of poisoning:

Death, vomiting.

Notes on poisoning:

A litter of 10-week-old pigs were given daphne berries and they died suddenly. The pigs had vomited before they died. Postmortem examination revealed white, burned patches in the mouth and an intensely inflammed stomach (Cooper and Johnson 1984).