By Dean Fosdick
For The Associated Press | Posted: Thursday, May 7, 2009 12:00 am
Lily-of-the-valley, clematis and chrysanthemums are attractive plants that can make your heart soar. Problem is, they're also capable of shutting it down.
All are commonly cultivated plants that are toxic if ingested by people or pets.
Just as many plants have the ability to heal, so thousands of ornamental plants have complex chemical compositions that make them capable of poisoning, said Michael Balick, vice president and director of the Institute of Economic Botany at The New York Botanical Garden.
"The concept of poison and the concept of medicine are closely aligned," he said. "You're usually talking about dosage."
Digitalis is a prominent example, said Balick, co-author of the "Handbook of Poisonous and Injurious Plants" (The New York Botanical Garden Press and Springer, 2007). "A certain dosage of the digitalis leaf could enable the pumping of the heart, where a larger dosage could kill a person," he said.
There were 60,514 cases of unhealthy plant exposure reported in 2007 to the nation's poison control centers, according to the federal Health Resources and Services Administration.
"This includes all routes of exposure, including swallowing plants, and skin reactions from such plants as poison ivy and poison oak," said David Bowman, an agency spokesman. Plants were cited in two fatalities.
Toxic plants do not pose as much danger as pharmaceuticals, but it pays to be cautious.
"Some plants can cause severe oral irritation if chewed," Bowman said. "Mistaking hemlock for carrots has been responsible for seizures and fatalities."
Many houseplants also are toxic.
"Chewing dieffenbachia or philodendron could cause oral irritation and swelling," he said. "Some other common indoor plants like African violet, jade plant and sansevieria are not poisonous but could cause stomach upset if swallowed."
If poison ivy or poison oak plants are burned, people inhaling the smoke could suffer the same ill effects in the respiratory tract as contact with the plants causes to the skin.
Reactions to plant toxicity range from minor to lethal, and also depend upon a person's health and age.
"Some people are more sensitive to things in the environment than others," said Rosie Lerner, an extension horticulturist with Purdue University.
Body weight plays a part, she said. Generally, the smaller the body, the less toxin required to make you ill.
"This is one reason why children are so vulnerable," she said. "An individual's metabolism also may play a role."
Proximity to poisonous plants doesn't mean people should shy away from gardening, Lerner said.
"A little common sense should prevail if you spend much time outdoors," she said. "Cover up. Wear long-sleeved shirts, long pants, closed shoes and socks and gloves. You should be wearing gloves anyway, to protect from cuts and scrapes that could lead to infection."
Choking is another threat, particularly for children.
"My daughter, when small, swallowed a leaf from a jade plant and began to choke. We had to clear her throat. It wasn't a soft leaf and it wasn't a pleasant experience," said Sue Kell, education director for the Blue Ridge Poison Center in Charlottesville, Va.
The hazards change along with the seasons.
"We know when August has rolled around because that's when the pokeberry calls start coming in," Kell said. "They're attractive and kids are fond of putting them in their mouths."
Mushrooms can be a problem because so many are poisonous, and many look alike.
"We've even had professionals - professors at universities - who have misidentified mushrooms and have gotten sick," said Kell.
And then there are the holidays, when many suspect plants and trimmings are brought into the house.
"We get a lot of calls about Christmas decorations," Kell said. "Holly berries. Mistletoe berries. Anything within reach or that might drop onto the floor."
One plant alleged to be toxic, the poinsettia, may not be - at least not to a significant degree. "It takes a huge quantity of (poinsettia) leaves to be poisonous to a human," Kell said.
Anyone working near potentially poisonous plants should follow a simple rule, Lerner said: "Don't put anything in your mouth you don't know anything about."
Tips for living safely around poisonous plants
There is no foolproof way to avoid poisonous plants. Perhaps the best course is to learn which varieties can harm people and pets, then decide if you want them on your property.
If you elect to display a few of the toxic beauties, here's how to reduce risks:
- Accurate and timely identification will speed diagnosis if you call a poison control center. Know the names of plants commonly found in and around your home. E-mail a photo of the suspect plant. Have some illustrated reference books on hand to help with recognition. Two helpful ones are "Handbook of Poisonous and Injurious Plants," by Lewis Nelson, Richard Shih and Michael Balick (New York Botanical Garden/Springer, 2007) and "The North American Guide to Common Poisonous Plants and Mushrooms," by Nancy Turner and Patrick von Aderkas (Timber Press, 2009).
- Clear away berries, seeds or any other suspect plant material to prevent it from being eaten by children, livestock or pets.
- Some plants are toxic when rubbed against the skin, including poison ivy, poison oak, sumac, nettles and euphorbia. Reactions can vary from minor discomfort, inflammation and swelling to hospital stays.
- Many bulbs, seeds and plant parts (such as from lilies, castor beans or mushrooms) are extremely toxic. Store them out of reach of children and well away from anything edible. Even experienced gardeners can mistake poisonous bulbs for harmless onions and bite into them.
- Teach children never to put plants in their mouths, or even to gather mushrooms and berries, since their juices can be absorbed through cuts or scratches.
- Some plants that aren't toxic to humans may be lethal to animals, and vice versa. Azalea, rhododendron, lilies and schefflera are commonly grown houseplants that can be hazardous to pets. "Lilies are especially toxic to cats, and can cause life-threatening kidney failure even in small amounts," the American Society for the Prevention of Cruelty to Animals says.
- Even non-toxic plants can be dangerous if swallowed. Leaves can lodge in throats and block airways.
- Post in a prominent place the national toll-free information numbers for poison-related emergencies. For help about exposure to humans, call 1-800-222-1222. For incidents involving pets, contact the ASPCA Animal Poison Control Center at 1-888-426-4435. A consulting fee may be charged, according to the ASPCA's Web site. Both numbers are good nationwide, 24 hours a day.