Toronto Master Gardener Factsheet    

Toronto Master Gardeners are trained volunteers dedicated to providing horticultural information to the public.

For answers to horticultural questions contact the Toronto Master Gardeners' Info Line at the Toronto Botanical Garden (416) 397-1345 (Mon. to Fri. 10 a.m. to 1 p.m and Sat., Sun. and Holidays noon to 3 p.m.) or our web site.

Links

 

 

Toronto Botanical Garden is a volunteer-based, charitable organization whose purpose is to inspire passion, respect and understanding of gardening, horticulture, the natural landscape and a healthy environment.

777 Lawrence Avenue East
Toronto, ON M3C 1P2
Tel. 416-397-1340
Fax. 416-397-1354
www.torontobotanicalgarden.ca

 

 

Poisonous/Toxic Plants

Print Version

What is a Poisonous/Toxic Plant?

All plants contain biologically active chemicals. Many of these chemicals have proven to be very useful. However, some contain chemicals that cause adverse effects if handled or ingested. These effects, which may be mild to severe, may occur suddenly or over time. Fortunately only a few have the potential to cause death.

Why be concerned:

It is important for gardeners and homeowners to understand that certain indoor and garden plants can have adverse effects if handled or ingested. It is very important that children be protected from these adverse effects and for parents and caregivers to know what to do if a child ingests or handles a nonfood plant.

Poisonous/Toxic Plants

Below is an introductory list of some common plants that are poisonous/toxic. The list is not a definitive list. Readers are encouraged to pursue additional information if they have concerns about plants in their homes or on their property.

Plant Poisonous Part Symptoms
Aconitum napellus: Aconite, Turk's Cap, Monkshood, Wolfsbane Entire plant, including possibly vase water Tingling and burning in mouth, throat, face, followed by numbness and constriction in throat. Speech may be impaired. Nausea, vomiting, vision disturbances and cardiac rhythm disturbances may follow. Fatalities have been reported where large doses were ingested. Pharmaceutical Workers handling large quantities have experienced severe skin rashes.
Agapanthus africanus: Agapanthus, African Lily, Lily-of-the-Nile Sap Causes skin rashes and may cause damage to eyes, mouth and throat on contact.
Agave americana: Agave, Century Plant, Maguey, American Aloe Sap If ingested the sap can cause nausea, vomiting and irritation of the digestive tract.
Aglaonema commutatum: Chinese Evergreen Entire plant Pain, swelling and intense irritation of mouth, lips and throat. Ingestion of a significant amount may cause swelling of the throat and dangerous obstruction of the airways.
Allium giganteum: Allium, Ornamental Onion Bulb, flower and stem Irritation of skin, eyes. Ingestion may cause stomach irritation, nausea and vomiting, especially in young children.
Alstroemeria species: Alstroemeria, Peruvian Lily Possibly entire plant Species contain an allergen, tulipalin, also found in tulips, which can cause skin rashes. Ingestion may cause nausea and vomiting if taken in quantity.
Anemone coronaria: Anemone, Wind Flower Entire plant and possibly vase water Protoanemonin causes inflammation, blistering and possibly ulceration of the skin and mucous membranes. Eating nay part leads to severe gastric irritation, vomiting and diarrhea.
Arum species: Arum, Cuckoo-Pint, Lords-and-Ladies, Adam-and-Eve, Black Calla, Solomon's Lily Entire plant Species contain calcium oxalate raphides. Ingestion may cause pain, swelling and intense irritation of the mouth, lips and throat. Also irritation of the digestive tract, nausea, vomiting and diarrhea.
Caladium species: Caladium, Angel Wings, Elephant's Ears Entire plant Species contain calcium oxalate raphides. Ingestion may cause pain, swelling and intense irritation of the mouth, lips and throat. Also irritation of the digestive tract, nausea, vomiting and diarrhea.
Capsicum annuum: Christmas Pepper, Pepper Plant, Red Pepper Fruit and seeds Fruit and seeds contain high concentrations of capsaicin which irritates mucous tissue. If eaten, they will cause a painful burning sensation in mouth and throat. If juice comes in contact with the yes, painful inflammation may result.
Chrysanthemum species: Chrysanthemum, Mum, Boston Daisy, Marguerite Daisy Leaves, stems, flowers Contain allergens, which cause allergic reactions in sensitized individuals. More than one exposure is often required before a person becomes sensitized. Initially, there may only be a little redness or rash but each re-exposure can cause the reaction to become worse. Mums are not generally regarded as toxic when eaten in small quantities.
Colchicum autumnale: Autumn Crocus, Meadow Saffron, Mysteria, Wonder Bulb Entire Plant Ingestion can lead to immediate burning in mouth and throat, intense thirst, nausea, abdominal pain, vomiting and severe diarrhea. Kidney damage may follow. Death is possible, principally through dehydration. This plant also may irritate the skin.
Coffea arabica: Coffee Plant Beans Green coffee beans contain up to 2% caffeine, which can have a strong stimulant effect on small children. The beans also contain coffee oils, which can cause nausea and vomiting in small children if ingested.
Colocasia esculenta: Colocasia, Elephant's Ear Leaves The tuber of this species is edible but the leaves are not. See Arum species.
Convallaria majalis: Lily-of-the-valley. Entire plant and vase water in which cuttings are kept This plant contains a glycoside that acts much like digitalis, the drug used to treat heart ailments. When ingested it may cause a slowing of the heart and heart rhythm disturbances that, in severe cases, can lead to death.
Cyclamen persicum: Cyclamen Tuberous root Ingestion can cause intense stomach cramps, vomiting and diarrhea
Cymbidium hybrids: Cymbidium orchid Entire plant Contain quinones that cause rashes when they come in contact with the skin of some individuals.
Delphinium species: Delphinium, Larkspur Entire plant, especially seeds and young plants Ingestion can cause nausea, vomiting and nervous symptoms such as agitation and depression. May be fatal if ingested in quantity.
Dieffenbachia species: Dieffenbachia, Dumbcane, Mother-in-Law's Tongue Plant Leaves, stems, latex Biting or chewing rapidly produces irritation and burning of the mouth, tongue and lips. The swelling may immobilize the tongue, interfere with swallowing and breathing and, in severe cases, cause choking. Symptoms may last for days.
Digitalis purpurea: Foxglove, Digitalis, Fairy Bells, Fairy Cap, Thimbles, Fairy Thimbles, Folks Glove, Throatwort Entire plant including possibly vase water Ingestion of any part of plant, even in small amounts, can lead to dangerous disturbance of heartbeat. Larger amounts may be fatal.
Epipremnum aureum: Pothos, Devil's ivy, Arum Ivy, Pothos Vine, Golden pothos, Taro Vine, Solomon Island ivy, Hunter's Robe, Variegated Philodendron, Golden Ceylon Creeper Entire plant  Species contain calcium oxalate raphides. Ingestion may cause pain, swelling and intense irritation of the mouth, lips and throat. Also irritation of the digestive tract, nausea, vomiting and diarrhea.
Eucalyptus species: Eucalyptus Entire plant  Eucalyptus oils are used medicinally but when a substantial quantity is consumed they can cause nausea, vomiting and diarrhea. The leaves can also cause skin rashes.
Euonymus species: Euonymus Entire plant Several species have been reported to cause nausea, vomiting and diarrhea.
Euphorbia lactea: Candelabra Cactus, Dragon Bones, Milk-striped Euphorbia milii: Crown-of-Thorns, Christ Plant Euphorbia tirucalli: Pencil Tree, Milkbush, Malabar Tree, India Tree Spurge, Monkey Fiddle Latex (the milky sap under the skin) The latex can cause severe skin rashes and, if it reaches the eyes, severe inflammation, If swallowed, the latex can cause nausea, vomiting and diarrhea.
Gladiolus hybrids: gladiolus, Glad, Corn Flag, Sword Lily Flowers Possible digestive upsets when eaten.
Hedera helix: English ivy Leaves and berries Ingestion of leaves or the bitter-tasting berries will cause a burning sensation in the mouth and may cause nausea, vomiting and diarrhea. Contact may cause skin rashes.
Hippeastrum species and hybrids: Amaryllis, Barbados Lily Entire plant especially bulb When ingested the plant, especially the bulb, may cause nausea and persistent vomiting and diarrhea.
Hyacinthus orientalis: Hyacinth Entire plant, especially bulb Bulbs that are refrigerated to force early blooming can lead children to assume the bulbs are food. Ingestion can cause cramping, nausea, vomiting and diarrhea.
Hydrangea macrophylla: Hydrangea, Hills-of-Snow, Hortensia, Leaves and flower buds Ingestion can cause vomiting, diarrhea, gasping and rapid breathing. In substantial quantities convulsions, coma and death may result.
Ilex species: Holly Berries In small doses Holly may stimulate the nervous system. In large doses the berries can cause digestive upset and depress the nervous system. Poisoning causes nausea, vomiting and diarrhea. The berries are a special danger to small children and may prove fatal if enough are eaten and symptoms are not treated.
Iris species: Iris, Flag, Fleur-De-Lys Rootstock Ingestion may cause pain in the digestive tract, nausea, vomiting and diarrhea. The rootstock can cause skin irritation
Lantana camara: Shrub Verbena, Yellow Sage Immature fruit, leaves Ingestion can cause stomach and intestinal irritation, muscular weakness, circulatory collapse.
Narcissus species: Daffodil Bulb

Ingestion even in small amounts can cause nausea, persistent vomiting and diarrhea, which may lead to dangerous dehydration in young children. Because bulbs are sometimes kept in the refrigerator to facilitate forcing children may mistake them for food.
Nerium oleander: Oleander Entire plant. Also toxic are nectar, smoke from burning, vase water and honey made from flowers Extremely toxic - a single leaf is considered potentially lethal. Symptoms begin several hours after ingestion and include dizziness, drowsiness, slowed pulse, cold extremities, impaired respiration, unconsciousness and possibly death.
Nicotiana species: Nicotiana, Flowering Tobacco, Nicotine Entire plant Nicotine is highly toxic. Ingestion of any species may result in nausea, sweating, vision disturbances, vomiting dizziness, vascular collapse, failure of respiration, convulsions and possibly death.
Philodendron species: Philodendron, Heart-Leaf Philodendron Leaves Ingestion can cause burning of the mouth, vomiting and diarrhea.
Rhododendron species: Azalea, Rhododendron Leaves, flowers, honey made from nectar Ingestion may cause nausea, salivation, vomiting, weakness, dizziness, difficulty breathing and loss of balance.
Ricinus communis: Castor Bean, Castor Oil Plant, Palma Christi Seeds and to a lesser extent leaves Seeds are contained in the fruits at the top of the plant. Most poisonings occur when the seeds have been well chewed Ingestion causes burning of mouth and throat, nausea, vomiting, stomach pains, diarrhea, convulsions and possibly death. 1 - 3 seeds may kill a child and 2 - 5 an adult.
Solanum pseudocapsicum: Jerusalem Cherry Fruit, possibly other parts Ingestion can lead to stomach pains, paralysis, vomiting, diarrhea, circulatory and respiratory depression, and possibly death.
Tulipa gesnerana: Tulip. Bulb Ingestion may cause vomiting and diarrhea.

How to Reduce Risks of Plant Poisoning:

  1. Identify your house and garden plants.
  2. Learn which plants are poisonous/toxic
  3. Teach your children never to eat nonfood plants
  4. Be prepared for emergencies

What to do if a Child Ingests a Nonfood Plant:

Keep calm and keep your child calm. By keeping calm yourself, you also help to keep your child calm. Stress can worsen the effect of any poisonous material.

Remove any plant material from your child's mouth and save it

  1. Examine your child and note any symptoms e.g. cuts, redness, blistering of skin, eyes, mouth, throat. Remain alert for any unusual behaviour.
  2. Find out how much material s/he has eaten. Get them to show you the plant and ask what parts were eaten e.g. flowers, leaves, berries, etc.
  3. If possible, identify the plant. Before a physician or the Poison Information Centre can help your child, they must have at least some information about the plant. The ideal is to provide both common name and botanical name but if that is not possible take the plant or a portion to the phone and be prepared to describe leaf shape, colour, flowers, berries, etc.
  4. Call the Poison Information Centre and follow their directions. Even if you believe the plant consumed is nonpoisonous, call them. Answering parents' questions and providing non-emergency help are some of the centre's important functions.
  5. If directed to a hospital or physician, take the plant along and include flowers, seeds, fruits or exposed bulbs to help with identification.
The Ontario Poison Information Centre: 416-813-5900

Toll Free: 1-800-268-9017

References:

  • The Toronto Botanical Garden Weston Family Library is an excellent source for horticultural information.
  • Foster, Steven and Roger Caras. A Field Guide to Venomous Animals and Poisonous Plants (Petersen Field Guide Series). Boston, U.S.A.: Houghton Mifflin Company, 1994.
  • Canadian Poisonous Plants Information System http://www.cbif.gc.ca/pls/pp/poison?p_x=px

 

Factsheets are produced by the Toronto Master Gardeners in association with the Toronto Botanical Garden. They provide introductory information about a broad range of horticultural topics and are intended for personal use and study purposes. Should your gardening group or organization wish to use multiple copies we ask that you inform the Toronto Botanical Garden at info@torontobotanicalgarden.ca.


Date revised: January 8, 2006