Poisonous Houseplants—Is My Plant Poisonous?

datura versicolor, close-up of flowers (syn. brugmansia v.), cool greenhouse, august, norfolk
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The idea that a houseplant could hurt pets or children is naturally unsettling, so many people ask: which houseplants are poisonous? The quick answer is that very few of the plants routinely grown indoors pose a serious health threat. It's also worth noting the difference between a plant that is toxic and one that causes allergic reactions. Allergic reactions are not considered poisoning, but they can be very serious nonetheless. Allergic reactions range in severity from contact dermatitis (rash and hives) to serious anaphylactic shock if the leaves are eaten. If you suspect a plant is causing an allergic reaction, allergy testing can help pinpoint the cause and plants in that family can be eliminated from the home.

Aside from allergens, some plants grown indoors are irritants or even toxic to various degrees. Fortunately, plants that are truly toxic, like the Datura, are rarely grown as houseplants. Instead, we're more likely to be dealing with plants that cause local irritation or skin reactions. Though avoiding contact with these types of plants can typically fix the issue, it's still helpful to know which plants could be a problem, at least so you can warn children and strangers before they potentially hurt themselves.

The most maligned houseplant is probably the poinsettia, which is also the world's most popular houseplant. Fortunately, there is no truth to this rumor: the poinsettia is not poisonous. Eating poinsettia leaves will not harm or kill pets or small children. However, because the plant belongs to the Euphorbia genus, its milky white sap can be a mild irritant. This is true for many plants with milky white sap, including Philodendrons and certain Dieffenbachia.

Here is a list of plants that are considered mildly toxic or poisonous, along with their level of danger:

  • Euphorbia species. All Euphorbia species contain a milky white sap that can be a local irritant. The level of irritation varies from species to species. Plants in this family include the poinsettia (Euphorbia pulcherrima), Christ plants (Euphorbia milli), crotons (Codiaem variegatum) and acalypha.
  • Araceae species, or aroids. Not all aroids are toxic, but many have a mildly toxic sap that can irritate hands and sensitive tissues. Plants that fall into this category include Dieffenbachia (also known as dumb cane), Aglaonema, Monstera delicious, philodendron, caladium, colocasia, and calla lilies (Zantedeschia).
  • Lillaceae species. Many plants in the Lillaceae family, including Amaryllis, contain toxic sap that can cause digestive upset if eaten.
  • Solanaceae species. Plants in the Solanaceae family can be toxic. These plants frequently bear attractive berries that are tempting for children and probably should not be grown where children might be tempted to try them. Solanaceae plants include Browallia, Brunfelsia, Datura, and Solanum pseudocapsicum (Jerusalem cherry). This is the same family of plants that contains the hot pepper (Capsicum) and potato. The Datura plant (Angel's trumpet) causes occasional poisoning because of rumors that its flowers can be used as a hallucinogenic drug. In fact, they are toxic and cause severe medical problems.
  • Apocynaceae species. This family contains some of the most dangerous plants in cultivation, including highly toxic plants that can cause major medical problems. Representative species include oleander (Nerium oleander), Allamanda species and hybrids, desert rose (Adenium), frangipani (Plumeria), and Mandevilla. In their native habitat, plants in this genus are used by native bushmen to create poison arrows.

If a Reaction Occurs

If you suspect that your pet or child is suffering from an adverse reaction caused by a plant, you should contact the appropriate medical authority. The National Poison Center can be reached at (800) 222-1222. When you call, make sure to supply the name of the plant in question.