Top 10 Common Plants That Are Poisonous

These plants might be pretty, but they also contain toxins and poison that could be harmful (or fatal) to humans and animals. Be alert to the dangers of these poisonous plants. Know how to identify these common culprits found in yards and woods.


English ivy (Hedera helix) is an indoor and outdoor ornamental creeping vine that can be found in all parts of the United States, Europe and even Canada. The most poison is found in the plant’s leaves and berries, although contact with any part of the plant can result in getting English Ivy poisoning. The poisonous toxins found in the plant are derived from the chemicals falcarinol and polyacetolene. The affects of English Ivy can range from moderate to severe.

#9 Easter Lily

Easter lilies are beautiful and always a sign that Spring is here.  But you may want to take care to keep these plants out of the reach of children and pets.  All parts of the Easter lily plant–leaves, stems and flowers–are considered toxic and should not be ingested. Symptoms include dizziness, stomach pain and possible collapse.  Most plants that are poisonous to humans will also be poisonous to pets, but they may affect animals differently. Easter lilies are known to be extremely toxic to cats, causing liver failure if not treated immediately, whereas dogs are not as affected.


Colocasia as well as its close relative, Alocacia, is a tuberous bulb plant growing from 3 – 5 feet. Generally they are grown outside in semi-tropical and tropical areas.  They are fun plants for children because of their fast growth and large, veined leaves.  This plant does contain oxalic acid as well as asparagines which can be poisonous to people and animals.  The leaves and stems are the most dangerous part of this plant.  In rare cases, oxalate plants may cause swelling severe enough to block the airways.  So do not let your children or pets chew on these plants.


This plant is known in the realm of herbal healing.  Native to the Caribbean, Latin America and South Africa, the aloe vera plant produces a clear, gelatinlike substance that soothes burns and relieves skin conditions such as psoriasis when used as a topical, but the aloe vera plant also has toxic tendencies.  Just below the outer skin of the aloe vera plant’s leaves is a layer of yellow juice. This juice, also known as the plant’s latex, contains a natural chemical called aloin. Aloin is a type of anthraquinone glycoside, which may irritate your skin if you have an allergy to latex. The skin irritation or allergy associated with latex is known as contact dermatitis, which produces a localized rash.  The ingestion of aloe juice or latex may also irritate the intestines when taken orally.


Daffodils are classified in the Narcissus genus which is mainly made up of spring-flowering bulbs native to Europe, North Africa and Asia.  All Narcissus species contain the alkaloid poison lycorine, mostly in the bulb but also in the leaves.  Daffodil bulbs can sometimes be confused with onions and lead to accidental poisoning.  Florists often suffer from “daffodil itch” which involves dryness, fissures, scaling and erythema in the hands, this is said to be blamed on the exposure to calcium oxalate in the sap.  The clear fact is children, adults, and animals should not eat daffodils.  Daffodils (Narcissus) are considered slightly poisonous.  They will mainly cause an upset stomach and possible vomiting if ingested.


You don’t expect to find rhubarb in a poisonous list, but it contains oxalate, which have been reported to cause poisoning when large quantities of raw or cooked leaves are ingested. Oxalates are contained in all parts of rhubarb plants, but especially in the green leaves. There is some evidence that anthraquinone glycosides are also present and may be partly responsible. The stalks contain low levels of oxalates, so this does not cause problems.  The bottom line on rhubarb is that you do not eat the leaves (leaf blades) but you can eat the stalk.


Wild Cherry trees are the largest type of cherry tree, capable of growing up to 100 feet.  They produce cherries that are reddish black in the summer.  The berries are not poisonous and can be eaten, but the wild cherry twigs and tree leaves contain prunasin, a cyanide that when ingested, can be fatal. The poison becomes harmful when the leaves are exposed to stress that causes them to wilt. The wilting breaks down the prunasin and releases the cyanide. Cattle and horses are the main victims of poisoning by wild cherry trees. Wild cherry trees are valuable in North America for their landscape appeal and for their wood, which is used in the manufacturing of fine furniture.


Delphinium is a genus of about 300 species of perennial flowering plants in the buttercup family Ranunculaceae, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. The common name is larkspur.  The flowers are beautiful and often used in centerpieces.  All parts of the plant contain an alkaloid, delphinine, so are very poisonous, causing vomiting when eaten, and death in larger amounts.  In small amounts, extracts of the plant have been used in herbal medicine.  Larkspur, especially tall larkspur, is a significant cause of cattle poisoning on rangelands in the western United States. Larkspur is more common in high-elevation areas, and many ranchers will delay moving cattle onto such ranges until late summer when the toxicity of the plants is reduced.Death is through cardiotoxic and neuromuscular blocking effects, and can occur within a few hours of ingestion.


Azalea are of the Rhododendron speciesThey are large shrubs or small trees with evergreen lanceolate to elliptical leaves and terminal clusters of large, attractive pink to purple flowers.  Andromedotoxins (grayanotoxins) are water-soluble diterpenoid compounds.  Leaves and flower nectar (including honey made from plant nectar) are sources of the toxin.  As little as 3 ml nectar/kg body weight or 0.2% of the body weight as leaves may be toxic or lethal.  It is especially important to keep these plants out of reach of your pets and young children where they may chew on them.


This evergreen shrub or small tree is classified in the genus Nerium.  Oleander is one of the most poisonous of the commonly grown garden plants.  Oleanders contain a toxin called Cardenolide Glycosides. The toxin is mostly contained in the sap which is clear to slightly milky colored and sticky. When ingested in certain quantities, this toxin can cause harm – and possibly death. The extremely bitter and nauseating taste of the sap (much like a rotten lemon) causes a mechanical reflex in the stomach which rejects and expels the vile substance. Although not impossible, a person or animal would have to have a strong stomach or no sense of taste for a dose of the toxin to be fatal.  Wash hands (and arms) thoroughly when finished working with the plant. Do not chew on any part of the plant. And do not use it as a skewer for food (or as a toothpick!). Steer clear of the fumes and never use the branches as firewood!






One comment

  1. Very informative, I have Azalia in hedge pots, I was thinking about putting another type of flowering hedge plant in anyway, but now I’ve learned they are toxic to cats & honey production I’m definitely getting rid of them for a native lily pilly type hedge with a strong sweet scented annually flower.

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