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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Do You Believe Poinsettias Are Poisonous?

This article was published originally on 12/8/1993
This question wasasked of 1000 Americans by the Society of American Florists in1993. The answer, 53% believed incorrectly that the plant ispoisonous to humans and animals. Another surprising answer, 52% ofthe floral clerks surveyed also believed that poinsettias arepoisonous.

While many older books list the poinsettia (Euphorbiapulcherrima) as poisonous, the U.S. Department of Agriculture andothers have been unable to find substantial evidence that anyonehas ever died from eating poinsettias. With the millions of plantssold yearly, surely someone would have developed severe problems ifthe plant were poisonous. Further research done at Ohio StateUniversity using rats again showed no toxicity symptoms. Theseanimals were fed amounts equivalent to 1 to 5% of their bodyweight. These levels would be equivalent to a 150 pound personeating 1.5 to 7.5 pounds of poinsettia. Researchers also analyzedthe leaves, bracts, stems and milky sap for chemicals commonlyconsidered toxic. None were found. The researchers, Robert P.Stone and W. J. Collins published their research results in Toxicon9:301-302(1971).

Even though the poinsettia is not poisonous, it can result inproblems for some people. The milky sap can cause an allergicreaction which results in skin irritations. The poinsettia tastesbitter and should still be kept out of the reach of curiouschildren and pets. However, this is the same precaution that should be taken with other plants in the home. The surprisinganswers to the survey show that those of us who work with thepublic still have a long way to go in order to dispel the poisonouspoinsettia myth.

Some of our other holiday plants require more concern.Mistletoe is a parasite of several species of trees in thesoutheastern and western U.S., but used widely indoors during theholiday season. The berries contain beta-phenylethylamine andtyramine, two amines known to be toxic. Ingestion of the berriescauses acute stomach and intestinal irritation, cardiovascularcollapse, and even death. Keep berries out of the reach ofchildren and pets. Holly berries are considered dangerous forchildren because they can cause vomiting, diarrhea, and stupor wheneaten in quantity. In many cases, when holly is purchased forindoor use the berries have been removed. The berries are quitefleshy and do not hold up well in transit. Instead, artificialberries may be attached.

The holiday season is filled with the enjoyment of manytraditional plants. Use caution with poisonous plants, and helpspread the good word about the poinsettia.

Poinsettia



This article originally appeared in the December 8, 1993 issue, p. 166.

Year of Publication: 
1993
Issue: 
IC-465(26) -- December 8, 1993