Toxic Plants

Jean Field, Extension Specialist, Horticulturist II

Poisonous plants have been on the planet since time began, providing us with properties used in medicines and poisons alike. Our contact or ingestion of poisonous plants can cause varying results from a minor skin rash or itchy eyes to difficulty breathing, coma and even death.

How can people and their pets be poisoned by plants?

*Eating plant parts: seeds, roots, flowers, bark, sap, leaves
*Touching plants, their leaves, sap, seeds, flowers, etc...
*Inhaling the pollen from blooms or smoke from burning plants
*Cooking food on the branches of poisonous plants

Let’s take a look at some of the more common plants found in our landscapes that are poisonous to us and our pets.

Brazilian pepper (Schinus terebinthifolius) One of the worst invasive exotic plants in central and south Florida, the Brazilian pepper causes more damage than simply choking out native ecosystems. Contact with this plant produces a rash similar to its cousin, Poison Ivy. When it blooms, it causes breathing difficulty in some people. The rash can cause inflammation of the eyes and face. Pruning the plant while in bloom is especially irritating. Eating the berries can cause vomiting and stomach irritation.

Cycads: King Sago (Cycas revoluta) is a favorite palm-like plant that is popular in Florida landscapes. Female plants produce red seeds and, if eaten, can cause bloody diarrhea, coma and paralysis. A local veterinarian explained how dogs that eat Cycad seeds go into liver failure. If eaten by humans, seeds of all Cycads are highly toxic and protective gloves should be worn when handling them. Crushed seeds have been used as a fish poison in Australia, the native country of these Cycads.

Lantana (Lantana camara) This popular butterfly-attracting perennial contains poisonous compounds in all parts of the plant, especially the leaves and green berries. A reported death of a child in Tampa resulted from eating the green berries. Handling the new leaves cause a skin rash in sensitive people. Livestock and pets are vulnerable to poisoning from eating leaves, stems and fruit.

Oleander- (Nerium oleander) I am always thankful when new residents to Florida ask me about the toxicity of the Oleander as this showy plant is quite deadly. Always keep children and pets away from eating any part of this plant! Eating one leaf can kill an adult human and children may be poisoned by carrying flowers around in their mouths in play. Skin rashes can occur on sensitive individuals who come in contact with either the green or the brown leaves. Deaths have occurred in people who roasted food on Oleander stems. It is a beautiful and tough plant for the landscape that should be used with extreme caution.

Poison Ivy (Toxicodendron radicans) A great source of wildlife food and brilliant fall color, Poison Ivy has driven many a hiker to an itching frenzy after brushing against the leaves. The oily sap found in all parts of the plant spreads easily by either direct or indirect contact. Direct contact results from touching the plant. Indirect contact, perhaps the trickiest to avoid, comes from touching animals or clothing that have sap on them. Touching someone’s gardening gloves or their clothing can transfer the Poison Ivy sap to you. Itching and swelling may appear in a few hours to a few days. Approximately 25% of people are not susceptible to poisoning from Poison Ivy, but repeated exposure may cause sensitivity. Eating of the berries and leaves has caused stomach upsets and even death. It’s a good idea to learn what Poison Ivy looks like, especially as a seedling, so you can avoid it at all costs.

Yellow Allamanda (Allamanda cathartica) This ever-blooming plant can be found in either vine or shrub form. The spiny, porcupine-like round seed pods are poisonous if eaten and the white sap can cause skin rashes in sensitive people. If you plant this beauty in your garden, be sure the non-sensitive person does the pruning. Keep fallen seed pods out of the reach of pets and young children

Protect your pets: Make a list of the plants in your landscape to determine if they are toxic to you and your pets. If you are unsure, contact us at the Pinellas County Extension: 12520 Ulmerton Road, Largo (727) 582-2110 or check the web resources below. A local veterinarian described the symptoms of plant poisoning in pets: “Most of our plant poisonings are due to ingestion. Symptoms include vomiting, anorexia, yellow mucous membranes (gums, whites of the eyes) and lethargy”.

If you suspect someone has been poisoned, immediately call the local Poison Control Center at (800) 222-1222. Their website contains information on poisonous plants, insects and snakes. http://www.poisoncentertampa.org/poisonous-plants.aspx
Post this information on your refrigerator to have it in a pinch.

We may not be aware that many plants in our own back yards have toxic properties. Until you know if you have toxic plants, keep pets and children from eating suspect leaves, seeds, fruit and other plant parts. Wear long sleeves when pruning or carrying vines and branches to protect your skin. A little research up front can prevent itching, burning and the potential of severe illness from affecting your family and beloved pets.

Printed Materials Referenced:
Cycads, David L. Jones, Smithsonian Institution Press, 1993
Guide to the Poisonous and Irritant Plants of Florida, Fl. Extension Service, Circular 441
Poisonous Plants of the Southern United States, Florida Extension Service
Poisonous Plants around the Home, University of Florida, Bulletin 175D

Web Sites Referenced:
http://brevard.ifas.ufl.edu/Forms%20and%20Publications/PDF/plants%20poisonous%20to%20pets.pdf

http://brevard.ifas.ufl.edu/Forms%20and%20Publications/PDf/poisonous%20plants.pdf

http://www.ansci.cornell.edu/plants/index.html

http://www.aspca.org/pet-care/poison-control/17-common-poisonous-plants.html