Understanding Poisonous Plants

Just because it is winter doesn’t mean some people can stop worrying about poisonous plants, said Sharon Yiesla, University of Illinois Extension horticulturist.

“Why talk about poisonous plants in winter,” said Yiesla. “Because there isn’t a young mother or a pet owner who hasn’t looked at their house plants and wondered if they are safe.

“Many house plants do have some poisonous property. Often these are plants that may cause dermatitis (skin irritation) or irritation and swelling to the lips and mouth if eaten.”

She added that the phrase ‘poisonous plant’ can cause some people to react (and sometimes over-react). Any plant with poisonous properties should certainly be taken seriously, but often the meaning of poisonous is misunderstood.

“The term poisonous does not necessarily mean fatal,” she said. “Included among ‘poisonous’ plants are plants that cause: a. irritation to the tissues of the lips, mouth and/or throat, b. gastric irritation (nausea, vomiting or diarrhea) when ingested, c. contact dermatitis, d. allergic reactions, e. an adverse effect on the cardio-vascular system, f. an adverse effect on the central nervous system, g. death.

“Another thing often misunderstood is that not every part of a plant is poisonous. Some plants may have both poisonous and edible parts--you can eat tomatoes, but you should not eat tomato plant leaves. Also, the time of year--stage of plant growth--may affect the toxicity of the plant and it’s parts. For example, Mayapple, a spring wildflower is considered poisonous and should not be ingested. However, the fruit, when fully ripe, is not poisonous.”

Yiesla said there are ways to minimize risk. First, know the botanical names of all plants in your home or office. Label each plant so that in time of emergency there is no doubt as to the identity of the plant. That way if you need to call a poison control center you can be clear about the plant which has been ingested.

Find out which plants in your home are poisonous. There are many websites that address this issue, both for humans and pets. Simply do an internet search using the phrase ‘poisonous plants’ and you will be directed to numerous sites. Plants that pose a serious health risk should be removed. Understand that exclusion of a particular plant from a poisonous plant list does not automatically indicate safety. There simply may not be enough information about the toxicity of that plant. No list includes every poisonous plant.

“Keep the phone numbers of the local poison control center and your family physician close to the phone. If you call the nation-wide number, 1-800-222-1222, it will route you to your local poison control center,” she said. “Be prepared for emergencies. Keep the following items available (to be used only on the advice of a physician): syrup of ipecac and activated charcoal. If ingestion of a plant occurs, make note, if possible, of which parts of the plant were ingested.
Below are some common house plants that do have poisonous properties. This list is not complete. If a plant is not included on this list, it is not an indicator that the plant is safe.