The presence of poisonous plants in (or around) your home could affect anyone, at any time. Many of the plants that are poisonous to humans are also poisonous to pets and livestock. According to the California Poison Control System, exposure and consumption of poisonous plants is ranked as the No. 5 most common incidence of poisoning. The CPCS also reports that 51 percent of all poison exposures involve children 5 years and younger, and that 94 percent of poison exposures occur in the home.

A very commonly planted shrub here in Bakersfield, which is considered one of the most poisonous plants in the Southwest, is oleander (nerium oleander). The toxic compound in oleander is a cardiac glycoside that, when consumed in relatively small amounts can cause dizziness, irregular heartbeat, nausea, convulsions and death. Oleander is toxic to humans, pets and livestock and as few as five to 10 medium-sized leaves can be lethal for a horse or cow.

Other common poisonous plants include poinsettias, lilies, sago palms, morning glories, some hydrangeas, and impatiens. This is by no means a complete list. The CPCS has a very thorough listing of poisonous plants at The report, titled "Know Your Plants," can be downloaded for free. A number of toxic plant resources are also posted on my website at

There are a number of substances produced by plants that can cause them to be poisonous. Some of the most common compound classes are oxalates, glycosides and alkaloids. Some plants even contain well-known poisons, like cyanide. The toxicity of a plant can vary from the leaves to the stem to the roots and it can also vary by season.

The toxicity of a plant also varies by species. Some species are more poisonous than others, meaning small amounts can be dangerous, while others are less poisonous, meaning that it takes a greater quantity for the plant to have an effect. The toxicity of the plant also depends on the weight of the individual consuming it. A lighter- weight person may be more susceptible than someone who weighs more.

In case of accidental exposure to a potentially poisonous substance, the CPCS recommends that you remain calm. If a patient is unconscious, having convulsions or any difficulty breathing, call 911. Otherwise, the CPCS can be reached toll free, 24 hours a day, seven days a week at 1-800-222-1222. For further information and first aid recommendations visit the CPCS website at

Tips to avoid poison exposure

Preventing exposure to poisonous plants is the best way to prevent potential poisonings and can be accomplished by following a few basic tips:

Consider removing toxic plants from your home or garden.

Know the common and scientific name of every plant you buy and own and keep a list for reference. This is best accomplished by labeling each plant. Show all caretakers where the labels and list are kept.

House plants should not be within reach of young children.

Store labeled bulbs and seeds out of reach of children and pets.

Do not eat plants or mushrooms collected outdoors unless you are certain they are safe.

Teach children not to put any part of a plant in their mouth.

Don't let children chew on jewelry made from seeds or beans.

Dispose of plant clippings in a safe manner. Do not allow children and pets access.

The smoke from poisonous plants can also be toxic; don't burn plant clippings unless you are certain they are safe.

In general, plants toxic to humans are also toxic to pets.

One of the tips above mentions mushrooms. Some species of mushrooms are edible, however, some species of mushrooms are quite poisonous and there is no easy way to tell the difference.

Eating any mushrooms collected outside should be considered dangerous and avoided.

Some symptoms of severe mushroom poisoning can include intense diarrhea and can lead to liver failure and death.

Call the CPCS if you believe someone has been poisoned. Do not wait until symptoms appear, as symptoms are sometimes delayed many hours, even in cases of severe poisoning.

Some plants and plant parts that are not poisonous to humans are poisonous to pets.

These include: grapes, raisins, macadamia nuts, onions and chocolate. A partial listing of human food that is poisonous to pets can be found at and

Be sure to talk to your vet to receive a more complete list and before feeding any human food to your pet as serious side effects can result.

Julie Finzel is the livestock and natural resources adviser with the UC Cooperative Extension in Bakersfield.