Poisonous Houseplants

Our family recently (November 2004) added two new puppies to the household. They are seven-week-old Chihuahuas and quite lively, not to mention entertaining. Like most “toddlers” they tend to get into everything and chew on everything but the chew toys. I’ve had to “baby proof” my house all over again, including taking a good look at the houseplants to assure poisonous ones are not within reach. 

Unfortunately, there are a few houseplants that are quite poisonous to humans and/or animals. Remember that there are three routes of exposure for poisoning: through the skin, inhaling through the nose, or eating. I’ll focus only on stomach poisons here that are a problem if eaten. With stomach poisons it is important to remember “the dose makes the poison.” In other words, an amount that won’t hurt a large dog might kill a small one. 

Dumbcane (Dieffenbachia sp.)

There are several houseplants that contain calcium oxalate, a chemical that causes severe burning and tongue swelling. Examples of plants with this chemical include dumbcane (Dieffenbachia sp.), heartleaf philodendron (Philodendron cordata), anthurium, caladium, Swiss cheese plant (Monstera deliciosa), spathiphyllum, arrowhead vine (Syngonium podophyllum), and devils ivy or pothos (Epipremnum aureum). Most of these plants cause painful and immediate swelling of the mouth and throat after chewing on plant tissue. Speech impediment can occur, sometimes lasting for several days.

Some plants contain latex type juices. Examples include aloe and poinsettia. Ingestion of the latex can cause a cathartic (purging) reaction by irritating the large intestine. The actual toxins in poinsettia are unknown, although it is no longer classified as extremely toxic. Reactions to poinsettia for humans range from dermatitis to nausea and vomiting. 

During the holiday season, also beware of toxic holiday plants. Holly berries (Ilex species) can induce vomiting, diarrhea and stupor. Holly foliage (Hedera helix) berries contain saponins, which can cause a burning sensation in the throat and gastronomical upset with vomiting and diarrhea. Jerusalem Cherry (Solanum pseudocapsicum) fruit or foliage should not be eaten. 

Mistletoe (Phoradendron species) berries may result in vomiting, diarrhea and moderate stomach and intestinal pain.  In severe cases there may be labored breathing, dramatically lowered blood pressure, and heart failure.

Please don’t despair. There are many houseplants and decorations that are not toxic. Example of nontoxic houseplants include African violet, baby tears, Boston fern, coleus, Christmas cactus, dracaena, jade, palm, pepperomia, prayer plant, sansevieria (Mother-in-Laws Tongue), schefflera, spider plant, Swedish ivy, wandering Jew, and zebra plant. 

Keep the toxic plants out of the reach of pets and children!

Originally Published in Canton Ledger Column on November 13, 2004