Poisonous Plants You Need to Know
By: Jo Ann McCall

Appalachian Niche Nursery & Services

 

Driving around the Lake Toxaway area, you hardly ever see any poison ivy, a plant which makes me seem to start itching just by merely looking at it! For those of you who don’t know, poison ivy (Toxicodendron radicans) if touched, can cause severe skin irritation to people who are allergic to the toxin found in the oil of the plant. If you don’t have poison ivy around your home or happen to not be allergic to it, consider yourself fortunate. However, you may be surprised to know that your yard, the woods around your house, and even your house may contain poisonous plants! But before you mix up the weed killer or throw out all of you houseplants, read on.

Many, many plants in the US are considered “toxic” and some plants are more toxic than others. When touched, some toxic plants cause skin irritation ranging from mild to severe. While other toxic plants, if ingested, cause symptoms ranging from mild stomach upset to death. The plants mentioned in this article are considered “highly toxic if ingested” by Dr. Alice B. Russell in her book, “Poisonous Plants of North Carolina”. This article is in no way a complete list of all the toxic plants in western North Carolina, but is simply an attempt to increase awareness about them and to provide additional sources of information for the reader.

You may be surprised to know that many common western NC landscape plants are poisonous to humans if ingested. For instance, all parts of the mountain laurel (Kalmia latifolia) are considered highly toxic. Also, rhododendrons and azaleas (Rhododendron spp.) are toxic if eaten. Some symptoms of ingesting rhododendron or azalea may include: nausea, vomiting, slow pulse, convulsions, and paralysis. All parts of the winter daphne (Daphne odora) shrub are highly toxic and may be fatal if eaten. Also, ingestion of the common perennials larkspur (Delphinium spp.) and Autumn crocus (Colchicun spp.) may cause numbness of throat, vomiting, respiratory failure and even death.

All parts of some plants may be toxic if eaten, such as the Calla lily (Zatedeshia spp.) and elephant ears (both Aocasia and Colocasia spp.). However, some plants like the Amaryllis may be toxic only if the bulb is eaten. Also, the leaves of Florida leucothoe (Agarista popufolia) and doghobble (Leucothoe fontanesiana) contain Andromedotoxin, which can cause severe symptoms, and even death. Other plants whose leaves contain Andromedotoxin include: Fetterbush (Lyonia spp.), Japanese andromeda (Pieris japonica), and mountain andromeda (Pieris floribunda). The Yew (Taxus spp.) is a plant commonly used in landscape design in NC. If ingested, this plant’s bark, leaves, and seed pits are toxic. Two other common toxic landscape plants are the laurel-cherry (Prunus laurocerasus) and the black cherry (Prunus serotina). Seeds and wilted leaves and stems from these plants can be toxic when eaten. The red buckeye (Aesculus pavia) tree’s seed, or “lucky buckeye” as some folks call them, are also considered highly toxic if eaten. Also, flowers, leaves, and seeds from the common foxglove (Digitalis purpurea) and the beautiful angel’s trumpet (Bugmansia spp.) can be toxic if eaten.

Berries of Virginia creeper (Parthenocissus quinquefolia), European bittersweet (Solanum dulcamara), and privet (Ligustrum spp.) can easily be found in the NC landscape. However, if eaten, these berries can cause a variety of symptoms including: nausea, vomiting, headache, weakness, abdominal pain, and possibly even death. Some native plants such as pokeweed (Phytolacca Americana) and mayapple (Podophyllum peltatum) are highly toxic, yet certain parts may possibly be made edible if certain precautions are taken. For instance, all parts of the pokeweed including the roots, shoots, berries, and mature leaves are considered highly toxic. However, young, tender leaves may be harvested and eaten if prepared properly. Also, the May apple’s root, leaves, and unripened fruit is considered highly toxic. Ripened fruit from the may apple may possibly be eaten in small quantities. However, I don’t advise eating any of the plants mentioned in this article.

Some plants which are not as harmful to humans may cause sickness and even death to dogs or cats. Common tulip and Narcissus bulbs contain toxins that, if ingested by pets, can cause many symptoms including: loss of appetite, convulsions and cardiac abnormalities. Also, all parts of the sago palm (Cycas revoluta), commonly found in homes and landscapes in warmer climates, are poisonous. However, the seeds or “nuts” of the sago palm contain the largest amount of toxin. Just 1 or 2 of these seeds may cause serious side affects such as: diarrhea, vomiting or liver failure in dogs or cats. Cat owners should be especially careful with plants in the Lily (Lilium spp.) family. Even ingesting small amounts of a plant in the lily family can result in severe kidney damage to felines. As if that wasn’t enough, the beautiful houseplant Cyclamen can produce gastrointestinal irritation, vomiting and even death if eaten by pets. For more information about plants that are toxic to pets, consult your veterinarian.

So, the next time you are outside gardening or walking in the woods with small children or pets, be aware that many common plants in the landscape can be harmful if swallowed! For more information on toxic plants, visit www.appalachianniche.com and click on more info.

Jo Ann McCall is a Certified Plant Professional by the NC Nurserymen’s Association. She owns and operates Appalachian Niche Nursery & Services which offers plant care services. She can be reached at:
(828) 553-2757.