Red-berried holly wreaths on front doors, beribboned sprigs of mistletoe strategically placed to encourage stolen kisses, a colorful poinsettia plant on the coffee table: young children often find these Yuletide symbols irresistible to touch and to taste, provoking thousands of frantic calls to poison control centers nationwide. Poinsettia and holly consistently rank among the top ten plants that callers ask about; mistletoe is a little further down the list. (Overall, one in ten emergency calls to poison control centers concerns plants.) Parents wonder, and they worry, and they call—although the children who prompt most of these calls usually show no actual signs or symptoms of distress.
Poinsettia (Euphorbia pulcherrima), also known as Christmas flower, is a member of the spurge family (Euphorbiaceae). In its native haunts in Mexico and Central America and in frost-free regions of Florida, Texas, the Southwest, and California, it is a woody shrub that may grow to 10 feet tall. Plants grown for the Christmas market are about 18 inches tall, and their showy, leaflike bracts below the tiny flowers may be white, pink, green, or variegated as well as the traditional vermilion. Poinsettia’s short-day flowering period makes it a good short-term houseplant for the Christmas season.
The genus Euphorbia comprises some 2000 species of herbs, shrubs, and trees that are found throughout the world. Many euphorbias are spiny and cactuslike. Most have a milky sap that contains irritating diterpenes, which can cause painful blisters when touched or gastritis when ingested.
Much of poinsettia’s popular reputation as a deadly poison derives from a 1919 report according to which a two-year-old boy in Hawaii died after eating a few of what were believed to be poinsettia bracts; however, the plant was never positively identified. Although the Swiss Toxicological Information Center reported a case of a dachshund that died after eating poinsettia leaves, other cases of human ingestion of poinsettia reported in the medical literature have produced nothing more severe than vomiting. In 1973, the arms and chest of a sixty-six-year-old greenhouse worker who had been cutting bunches of poinsettia without a shirt on became inflamed, and he ran a high fever. His reaction was attributed to allergic hypersensitivity. Poison control centers in the United States apparently have had no reports of contact dermatitis.
The cheerful evergreen leaves of holly are adorned with brilliant red fruit. Both the American Ilex opaca and the European I. aquifolium are grown in the United States and supplied to florists during the holiday season. The fruits are rather dry and bitter and contain toxic saponins. Consumption of two or more of the berries has been known to cause nausea, vomiting, and diarrhea. The usual treatment includes administering fluids to prevent dehydration from the vomiting and diarrhea. Deaths were reported in the early medical literature, but recent reports mention only minor symptoms.
In investigating holiday plant decorations, children are less likely to encounter the translucent white fruits of mistletoe because the sprigs are generally hung out of their reach. The mistletoe family (Viscaceae) has numerous representatives in North America; in addition, European mistletoe (Viscum album) is naturalized in a small area of California.
Phoradendron leucarpum (syn. P. serotinum), found in the eastern United States from New Jersey to Florida and west to eastern Texas and Missouri, is the species used for decoration at Christmastime. These parasitic plants often live high in oak trees, and they are commonly harvested by blowing them out with a shotgun. Here in the Ozarks, sprigs of this species are readily available at this time of year at farmer’s markets, on street corners, and at malls.
The stems, leaves, and, to a lesser degree, the fruits of this species contain toxic lectins (toxalbumins), which may inhibit the synthesis of proteins in the intestinal walls. Similar compounds are found in the leaves of European mistletoe but are absent from its fruits. It has been reported that eating only a few berries of the American species has produced abdominal pain or diarrhea. Some florists offer mistletoe with artificial berries to eliminate the danger of poisoning.
A little common sense will go a long way to ensure a safe holiday, unmarred by a scare or a panic call to a poison control center. Keep poinsettias, hollies, and mistletoe out of reach of pets and small children and warn older children who can understand the dangers against eating the colorful leaves or fruits of these plants. If you are making holiday decorations out of poinsettia, remember that the latex in the stem may cause contact dermatitis in sensitive individuals. And know where that poison control center number is—just in case.
May your holidays be filled with joy and health.
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