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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.

Poisonous Plants

This article was published originally on 7/15/1994
Potentially poisonous plants are a concern to everyone, especially when young children are present. Poisonous plants can be separated into different groups based on their toxicities. Some plants will cause a systemic toxicity resulting in a range of symptoms from mild abdominal cramping to serious cardiac arrest. The degree of toxicity depends on the quantity ingested or the part of the plant eaten. Other plants contain insoluble calcium oxalate salts. Poisoning results in a burning sensation due to the irritation of mucous membranes. The ground glass consistency of the salts can also irritate hands or skin. Other plants contain soluble oxalate salts. These produce much the same symptoms as those with insoluble calcium oxalate salts; however, these salts can also be absorbed into the body which can damage kidneys and other organs. Individuals need to ingest large amounts of plant material to absorb enough of the salts to cause damage. Finally, some plants contain chemical substances that cause stomach upset or, after skin contact, dermatitis. Several things can be done to minimize potential plant poisoning problems.

If small children are part of the picture, avoid the use of plants with known poisonous properties especially those with poisonous berries or other attractive above ground features. Plants with poisonous root systems are less likely to cause problems since the roots are not readily visible. Teach children at an early age not to play with plants or eat berries or other plant parts without permission from a knowing adult.

An important step in minimizing problems is to label plants or have a landscape plan that identifies the plants in the yard and garden. In the event of an exposure to any potential plant poisoning the first thing the poison center will want to know is the plant name. It is important to have the latin name for the plant rather than the common name. Only one plant can have that particular latin name; however, several plants can be known by the same common name.

Some plants are known to cause skin irritations for some individuals. Locate these plants away from sidewalks and paths so people aren't as apt to brush against them. In the case of potential skin irritation, wash thoroughly with soap and water the skin areas that may have come in contact with the plant. In many cases, washing immediately will greatly reduce the irritation.

Pets eating plant material can also be a cause for concern. Unfortunately, some plants that are non-toxic to humans can be dangerously toxic to cats and dogs. Much of the literature available is based on human exposure rather than domestic animals. Local veterinarians will have information on pet poisoning. Poison control centers can also provide information.

If a potential poisoning occurs, don't panic (easier said than done)! Remove any plant parts remaining in the mouth. Try to determine how many berries or how much of the plant the individual ate. Eating any unidentified berry, plant, mushroom, or toadstool requires prompt medical assessment. Call a physician or the poison information center (1-800-272-6477) for the best course of treatment, which varies on a case-by-case basis.

This article originally appeared in the July 15, 1994 issue, p. 111.

Year of Publication: 
IC-467(18) -- July 15, 1994