Garden Note 21

Common Poisonous Plants in Home and Grounds

The poisonous properties of plants are found in many forms but can be roughly classified into seven groups:

1. Alkaloids-These are perhaps the most common. Over 100 types are known, including some known well in medicine, such as atropine, lobeline, nicotine and codeine.
2. Glucocides-Crystalline materials which are decomposed by enzymes to produce toxic effects. A well-known material in medicine is digitalin, a heart stimulant.
3. Organic acids-Usually form in the body from enzymatic action on other materials. Prussic acid is a good example.
4. Neutral Principles-Crystalline bodies of varying effects. Coumarin is in this group.
5. Resins-Complex materials formed from volatile oils.
6. Volatile oils-Such as those found in Euphorbia (spurges). Some of the juices cause severe skin reactions.

The modes of action of the various poisons in plants are usually classed into four groups:

1. Those acting on the brain causing narcotic reactions and other mental disturbances;
2. Those affecting the spinal cord resulting in paralysis and convulsions;
3. Heart depressants and stimulants; and
4. Irritants of the digestive tract, nervous system, and skin.

Because a plant or a part of a plant in your home or yard contains a poison is no reason to destroy it. Many, while containing poisons, must be ingested in such large quantities that the incidences of actual poison cases are rare. Simply heed the following safety rules and you should have no cause for concern:

1. NEVER eat any part of an unknown plant whether in your yard or in the wild.
2. NEVER chew on jewelry made from plant parts such as seeds. Children should not be allowed to use them for teething or "play jewelry."
3. NEVER attempt to make your own "nature tea" unless you know the plant you are using and you know that the recipe is from an authoritative source.
4. IF YOU GROW YOUR OWN HERBS for cooking, make sure they are properly identified. Some poisonous plants resemble common herbs.
5. DO NOT ALLOW CHILDREN to pick anything in the yard without your supervision. This rule should apply even for your garden vegetable and fruit. Remember that children are naturally curious and will try almost anything once. Even bitter-tasting leaves and tart green fruits won't stop them.
6. Store seeds, bulbs and similar materials saved for replanting away from children. Label fully.

The U. S. Public Health Service reports that about 12,000 children ingest poisonous plant parts each year. Many of these are so common that their toxic qualities are not suspected.

If a poisoning occurs or is suspected, CALL YOUR PHYSICIAN IMMEDIATELY. If your physician is not available, contact the nearest POISON CONTROL CENTER. In North Carolina call either 1-800-848-6946 or 1-800- 672-1697.

Save all evidence that would be helpful in identification of the poison source and type such as the plant or plant parts and sputum.

The following is a list of plants which are relatively common in and around the home or adjoining uncultivated "wild" areas.

The toxic substances, where known, are given to provide reference for poison control centers and others in the medical profession.

It would be desirable to construct a list of poisonous plants according to their degree of danger but too many factors are involved to make such a list practical. Factors which determine the relative toxicity of a plant include:

1. age of person in relationship to quantity ingested;
2. the form that the plant part was in at time of ingestion (i. e. cooked vs. uncooked, ripe fruit vs. unripe, etc.); and
3. the relative attraction or appeal that a plant possesses such as showy "edible-looking" fruit.

For purposes of the plant list, those plants most likely to entice children are considered the most dangerous. These are indicated with an asterisk (*). All others in the list can be considered less dangerous, even though some are more toxic, because they are less likely to be eaten.

Plant	Toxic Part	Toxic Substance and Symptom
Azalea (Rhododendron species)	all parts	Alkaloids-Produces nausea, difficult breathing, coma. Fatal.
*Castorbean (Ricinus communis)	seed pulp (oil safe)	Contains a glucoside, ricin and an alkaloid, ricinone. A strong purgative. Two seeds, if chewed, can be serious; eight seeds are considered lethal.
Daffodil species)	seed pulp	Contain narcissine, an alkaloik. Causes acute gastrointestinal problems. May be fatal.
Dumbcane (Deiffenbachia)Caladium is similar	all parts	Calcium oxilate crystals causing intense burning and mouth irritations. Death may result where tongue swelling has blocked air passage.
Elephant's Ear (Colosasis antiquorum)	all parts	Same as Dumbcane
Hyacinth (Hyacinthus orientalius)	bulb	Same as Daffodil.
*Misletoe (Phoradendron flavescens)	berries	Strong amines. Several deaths among children eating berries have been reported.
Oleander (Nerium oleander)	all parts	Heart stimulant similar to digitalis (see Foxglove under garden flowers).
Poinsettia (Euphorbia pulcherrima)	leaves	It can irritate the digestive tract when eaten and cause vomiting and nausea.
*Rosarypea Precatory-bean (Abrus precatorius)	seeds (glossy scarlet and black seeds commonly used in imported jewelry.)	Considered among the most toxic of natural materials. Less than one seed, when chewed, has caused death in children.

Plant	Toxic Part	Toxic Substance and Symptom
Autumn,crocus (Colchicum autumnale)	bulb	Contains colchicine which will cause vomiting and nervous excitement.
Bleedingheart (Dicentra species)	foliage, roots	May cause convulsions and labored breathing when eaten in large quantities.
Buttercup (Ranunculus)	all parts	Contains glucoside which acts as an acrid narcotic. Paralysis results from large doses.
Delphinium and Larkspur (Delphinium species)	all parts	Alkaloids (5 types) which produce severe digestive upset and nervous excitement.
Foxglove(Digitalis purpurea)	leaves and seeds	Contains digitallin and other glucosides which stimulate heart action. Overdose is usually fatal.
Iris (Iris species)	all parts	Contains the clucoside irigenin and acrid resin, iridin. Causes acute gastrointestinal problems.
Leopardsbane (Doronicum species)	leaves	Contains arnicin causing a skin rash in some people.
*Lilly-of-the-valley (Convallaria majalis)	all but ripe fruit	Contains convallamarin and convallanin. The former acts like digitalin (see Foxglove) and the latter is a purgative.
Monkshood (Aconitum species)	leaves, stems and roots	Contains several alkaloids related to aconitine. Some species of Aconitum were used for arrow poisons in India. Death is sudden.
Morning-glory((Ipomoea species)	seeds (roots of the native species, I. lepophylla are edible.)	Produces LSD-like effects but can cause death from severe mental disturbances.
Pinks (Dianthus pllumarius and others)	leaves	Contains saponins which disolve blood corpuscles.
Peony (Paeonia officinalis)	roots	Contains acrid juice which causes paralysis.
Snowdrop (Galanthus nivalis)	bulb	Contains narcissine. Symptoms like those of Hyacinth. (See under HOUSE PLANTS.)
Spurge, Snow-on-the-Mountain (Euphorbia-several species)	leaves	Contains euphorbin and other principles that are strong purgatives. Some people obtain rash from milky sap.
Ornamental Sweetpea (Lathyrus species)	seeds	In large quantity, seeds can cause death due to prussic (hydrocyanic) acid.
Violets (pansies) (Viola cornuta V. tricolor and others)	seeds (Flowers and leaves are edible).	Contains glucosides and myrosin. In quantity the cathartic effects can be serious to a child.

Plant	Toxic Part	Toxic Substance and Symptom
Potato (Solanum tuberosum)	all green parts	Strong alkaloid causing cardiac depression. Can be fatal.
*Tomato (Lycoperscion esculentum)	green parts	Same as in potato. Fried green fruit is edible.
Rhubarb (Rheum rhaponticum	leaf blade (stalk is edible)	Oxalic acid. Causes kidney rupture.

FIVE SAFETY RULES

• NEVER eat any part of an unknown plant whether in your yard or in the wild.

• NEVER chew on jewelry made from plant parts such as seeds. Children should not be allowed to use them for teething or "play jewelry".

• NEVER attempt to make your own "Nature tea" unless you know the plant you are using and you know that the recipe is from an authoritative source.

• IF YOU GROW YOUR OWN HERBS for cooking, make sure that they are properly identified. Some poisonous plants resemble common herbs.

• DO NOT ALLOW CHILDREN to pick anything in the yard without your supervision. This rule should apply even for your garden vegetables and fruit.

IF YOU SUSPECT A POISONING, CALL YOUR PHYSICIAN or CALL YOUR HOSPITAL

BE SURE TO SAVE ALL AVAILABLE EVIDENCE SUCH AS PLANT PARTS FOR IDENTIFICATION

E-mail me at:

MGVCumberla@hotmail.com

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This information compiled by Cumberland County Master Gardeners.
This page created on June 29, 1998 and updated December 14, 1998.