Beautiful Poisonous Flowers - Learn Which Flowers Are Not Edible

With the trend of edible flowers being used more widely in and on our food, it’s important to be aware which are poisonous flowers and so should not be eaten. We have many beautiful poisonous flowers growing in our gardens. They look beautiful in the garden and in the vase, but if ingested they can cause sickness and sometimes in extreme cases fatality.

What You Can Learn Below:

It’s also important to mention that many flowers that are commercially grown are also toxic because of modern growing practices. If you’re going to use flowers for the plate, then make sure you know that it has been grown organically and without the use of pesticides and fungicides. You can of course find easy edible flowers to grow yourself.

Which Flowers Are Poisonous?

The toxicity of flowers is caused by the presence of alkaloid and glycoside components that are produced by the plant usually as a form of defence against being eaten by herbivores. The levels of toxicity vary within parts of the plant itself. Often the flowers are not toxic but other parts of the plant will be highly toxic.

So, it is very important that before using any flower on your food that you know which flowers are poisonous.

Tulips is one flower species which have caused some controversy as to whether they are toxic flowers. There have been many articles written that claim that tulip flowers are edible. It is the tulip BULB that is considered poisonous. Having said that it has been well documented that tulip bulbs were eaten during the European famine after WW2.

So, my advice would be don’t eat any flower or plant that you are not sure about!

A List of Poisonous Flowers with Pictures

This list is by no means exhaustive, but it has some of the more common garden flowers that are poisonous flowers or toxic flowers.

Click on the picture for descriptions of each of the poisonous flowers and their effects.

Alstroemeria (Alstroemeria spp)

Amaryllis (Amaryllis belladonna)

Angel Trumpet (Brugmansia spp)

Bleeding Heart (Lamprocapnos spectabilis)

Calla Lily (Zantedeschia aethiopica)

Castor Oil Plant (Ricinus communis)

Daffodil (Narcissus)

Desert Rose (Adenium obesum)

Foxglove (Digitalis purpurea)

Hellebore (Helleborus spp)

Hydrangea (Hydrangea spp)

Iris (Iris spp)

Larkspur (Delphinium consolida)

Lily of the Valley (Convallaria majalis)

Monkshood (Aconitum napellus)

Morning Glory (Ipomoea purpurea)

Oleander (Nerium oleander)

Sweetpea (Lathyrus odoratus)

Poisonous Flowers and Their Effects

Alstromeria (Alstromeria spp)

Alstromeria or Peruvian Lilies

Alstroemeria or Peruvian lilies as they are commonly known, are one of my favourite cut flowers. However, the whole plant is considered toxic. When the plant is cut or damaged it produces a compound called tulipalin. Tulipalin is a contact allergen which means it can cause irritation or blistering when in contact with the skin. If ingested it also causes vomiting and diarrhea if eaten although it is considered to have a low toxicity.

I have grown and used alstroemerias as a cut flower for a long time and have never had any of these problems. But it is important to be aware of the possibilities. It is not an edible flower – so needs to go on the toxic flower list!

Amaryllis (Amaryllis belladonna)

Amaryllis are pretty pink lilies that are native to Africa and appear on naked stems in the spring.

The whole plant has a low toxicity but vomiting and abdominal pain can be caused by lycorine and other alkaloids.

However, it is considered a low severity and tends to affect pets more than humans.

Angel Trumpet (Brugmansia spp)

The Angel Trumpet plant has beautiful flowers that are poisonous. In fact every part of the angel trumpet plant is highly toxic. The leaves, flowers, seeds and roots all contain the toxic alkaloids scopolamine, altropine and hyoscyamine. If ingested this can lead to hallucinations and fever, increased pulse rate, and dilated pupils.

It is considered to cause serious poisoning and can even lead to paralysis and convulsions. This is one plant that you need to be very careful with, to ensure that it doesn’t get into your body.

These are definitely poisonous flowers!

Bleeding Heart (Lamprocapnos spectabilis; formerly Dicentra spectabilis)

Bleeding Heart (Lamprocapnos spectabilis)

All parts of the Bleeding Heart plant is toxic if ingested.

This is due to the isoquinoline alkaloids which are present and are toxic to both animals and humans.

Touching or handling the plant may cause skin irritations but if ingested in large quantities this can lead to liver damage and seizures.

However, this is a very rare occurrence with humans but still is one of the poisonous flowers to avoid.

Calla Lily (Zantedeschia aethiopica)

The Calla Lily or Arum Lily is a common plant found in gardens. Although the level of toxic risk is not high for humans these plants do need to be respected for being able to release toxic compounds. All parts of this plant including the flower, contain calcium oxalate crystals, with the most toxic part being the roots. These crystals are released when the plant is cut or damaged and so care should be taken when handling. If sap enters the eye this can cause swelling and burning pain. If any part of the plant enters the mouth, this will result in painful burning of the lips, swelling of the tongue and throat. In more severe cases it can cause nausea and vomiting as well as voice hoarseness.

Castor Oil Plant (Ricinus communis)

The Castor Oil plant is a common weed that is frequently found along roadsides and common areas. It is a highly toxic plant. All parts of the castor oil plant can cause poisoning although the seeds or beans are the most toxic. The seeds of the castor oil plant are extremely poisonous because of the toxin ricin that is released once the beans are chewed or broken down. It has been reported that one seed can be fatal to a child.

Ricin is a known poison that is highly toxic to both humans and animals and can cause severe gastrointestinal irritation with vomiting, diarrhoea, and bleeding.

Irritation to breathing and sight may occur due to proximity to the plant particularly when its in flower.

Daffodil (Narcissus)

The daffodil is one of our most popular and common of spring bulb flowers. However, all parts of the daffodil plant contain the toxic chemical lycorine, with the highest concentration being in the bulb. So, enjoy daffodils growing outside or in the vase but don’t use them on the plate. Although considered relatively low toxicity, the effects of the lycorine can cause nausea, vomiting, diarrhea, and abdominal pain.

The bulb also contains oxalates which when ingested produce microscopic, needle like crystals that causes severe burning and irritation to the lips, tongue and throat.

So, enjoy daffodils growing outside or in the vase but don’t use them on the plate!

Desert Rose (Adenium obesum)

This lovely plant is a native to Africa and is hardy and drought tolerant, rewarding you with beautiful blooms in the wet summer months. Its fat and bulbous like trunks store water for the drought times. Despite being fascinatingly beautiful the Desert Rose is poisonous to both humans and animals.

It is the sap in the Desert Rose that contains the toxins known as cardiac glycosides and cardioactive steroids. These substances disrupt the central nervous system, gastrointestinal tract, and the cardiovascular system, therefore no part of this plant should be ingested. But it is still a great little plant to grow and enjoy in a container or in your garden.

Foxglove (Digitalis purpurea)

Foxgloves are fondly grown in many cottage flower gardens and are a lovely addition to the early summer array of blooms. The beautiful stems of bell like flowers are symbols of ambition, creativity, confidence, and productivity.

All parts of the foxglove contain toxic cardiac glycosides which can have severe effects on the heart function if ingested. This includes the berries, leaves and particularly the roots.

The foxglove does contain the compound digitalis which is used in treating heart failure. However, this cannot be taken in its raw form without severe health consequences.

Hellebore (Helleborus spp)

Also known as the Christmas Rose, this great little plant is also one of those beautiful poisonous flowers.

The toxic part of this plant is the leaves, stems and roots which all contain cardiac glycosides such as helleborin. This causes vomiting, diarrhea, dizziness and heart function disturbances.

The sap also contains saponins which causes skin irritability and sometimes blistering.

Hydrangea (Hydrangea spp)

Hydrangea florets are pretty, and I have occasionally seen them as a garnish to cakes. This should not happen! They are toxic and should not be used near food!

They contain cyanogenic glycosides which when crushed or eaten produce amounts of cyanide.

If consumed this can result in nausea, vomiting, and diarrhea.

Pets should not be allowed to eat any form of this plant.

Iris (Iris spp)

Irises are a stunning and diverse group of perennial flowering plants and well known for their striking and elegant flowers on tall stems.

Irises, while not highly toxic, contain compounds that can cause mild irritation or discomfort if ingested. The rhizomes, which are the underground stems of the plant, contain a compound called iridin. Ingesting large quantities of iridin may lead to irritation and inflammation of the digestive tract, resulting in symptoms such as nausea, vomiting, and abdominal pain.

Larkspur (Delphinium consolida) & Delphinium (Delphinium elatum)

Both the larger known Delphinium and the more commonly grown cottage garden flower Larkspur are part of the same family of beautiful but deadly flowers.

These lovely tall flowers with pretty blooms all the way down the flower stem contain the toxin alkaloid delphinine which causes severe neuromuscular effects in both animals and humans.

However, as is the case in most of these flowers, if you keep them in the garden or in the vase, they don’t pose a problem.

Don’t allow your pets to eat them either.

Lily of the Valley (Convallaria majalis)

Lily of the Valley is mostly known for its strong floral scent, which has traditionally been made into perfumes and fragrances. The blooms are cute little white bells hanging off the stem which look simple but very elegant.

The Lily of the Valley plant contains over 30 cardiac glycosides which is the toxin that affects the cardiac pumping in the body. The most common effects are slow and irregular pulse, heart arrhythmia, stomach aches and blurred vision. The roots have the highest concentration, but all parts of the plant are poisonous. The red berries that are produced after the flowers, have been known to have poisoned children who have been attracted by the bright red colour.

Monkshood (Aconitum napellus)

This plant is also known as wolfsbane and is often grown for its attractive dark blue to purple flowers. All species of monkshood are toxic to both humans and animals due to the presence of Aconitine.

This toxin is the most dangerous of several toxins present in the plant and is particularly concentrated in the roots, seeds and early leaf growth.

It is known as a heart poison but is also a potent nerve poison. It has been used since ancient times as a poison used on arrows and hunting spears.

Morning Glory (Ipomoea purpurea)

The flowers are not dangerous and can be edible. It is the seeds that are the toxic part of Morning Glory particularly if eaten in large quantities.

The chemical contained in the seeds is lysergic alkaloids which is similar to LSD and can cause hallucinations.

It can also upset the digestive system and cause nausea and vomiting.

Oleander (Nerium oleander)

Oleander is a very common plant, used extensively by urban landscapers due to its drought tolerance and hardiness. However, it has become known as one of the most toxic and potentially dangerous plants that we find commonly in our immediate environment.

The flowers are attractive and fragrant but are extremely poisonous if ingested and are known to be fatal to children. All parts of the Oleander plant are toxic and it needs only a very small amount ingested to produce dangerous symptoms such as dehydration, fever, slow heartbeat, which can lead to seizures and coma.

Cardiac glycosides are the main compounds of which Oleandrin is the principal toxin and is very dangerous. The bark contains rosagenin which when burned produces strychninelike actions if inhaled.

Sweetpeas (Lathyrus odoratus)

The sweet pea is an absolute favorite which grows quickly and flowers abundantly with beautiful clusters of butterfly shaped blooms which have a sweet fragrance.

Despite the sweet pea being so charming, it contains compounds that can be toxic if ingested. The compound known as amygdalin is particularly concentrated in the seeds of the sweet pea and releases cyanide when metabolized by the body. This can cause symptoms such as nausea, vomiting, abdominal pain, and difficulty breathing. While the risk of toxicity from handling the plant or its flowers is low, caution should still be exercised to prevent accidental ingestion.

More Poisonous Flowers

Other well known toxic flowers are:

Yesterday, Today, Tomorrow (Brunfelsia spp)
Lily
Cyclamen
Poinsettia
Peace Lily (Spthiphyllum)
Azaleas
Rhododendrons
Poison Hemlock (Conium maculatum)

There are more poisonous flowers than I have mentioned in this article.

If you’re not sure if a flower is edible, then take the safe approach and don’t eat it until you have done some research.

Beautiful Poisonous Flowers - Learn Which Flowers Are Not Edible

Which Flowers Are Poisonous?

A List of Poisonous Flowers with Pictures

Poisonous Flowers and Their Effects

Alstromeria (Alstromeria spp)