Top 10 Beautiful but Poisonous Flowers in the World

Some flowers that seem innocent and beautiful may be inherently poisonous. Though harmless they appear, the toxins and poisonous substances the flowers produce can be toxic or even deadly to humans and other species. But, these fatal poisons are nature’s blessings as a means to defend themselves from danger.

So, let’s dig into the list of top 10 flowers that seem beautiful but can harbor poisons.



Image credit: Ian Lee on Flickr

Hydrangea is a widely cultivated deciduous species native to the temperate areas of Asia and the Americas. Flower changes its color based on the soil’s pH. If the flower is blue, the soil is acidic, and pink indicates alkaline soil. Entire parts of the plant are poisonous, and a high concentration of toxins is present in leaves and flowers. 

The leaves and flower buds of hydrangea contain “amygdalin,” a cyanogenic glycoside that causes allergic reactions and some clinical signs, including vomiting, Diarrhea, and depression. Amygdalin is not that poisonous in its normal form. But when metabolized within the body, it produces hydrogen cyanide which causes a severe lack of oxygen by interrupting the working of an enzyme needed for the respiratory chain action. 

The extent to which hydrangea can be poisonous depends on the amount of intake. Our immune system reacts to these toxins through itches and burns in the affected area. A feeling of dizziness, shortness of breath, and anxiety are some symptoms caused when consuming a large amount of the plant. 



Daffodils are vibrant and fragrant flowers that usually appear in bright yellow or white blooms in early spring. All parts of the daffodils are poisonous due to a chemical compound called lycorine, and its high concentration is present in the bulb. Eating daffodils can cause symptoms like vomiting, abdominal pain, nausea, and diarrhea. 

Usually, the symptoms can’t last more than 3 hours. But in the worst situations, low blood pressure or even damage to the liver can happen by consuming the flower in large quantities. Even though these symptoms are not deadly, it takes a few hours to recover completely.

Daffodils also contain calcium oxalate crystals. The primary symptoms are a burning sensation on the skin and immediate pain in the mouth. But the difficulty in swallowing and swelling can also happen due to indigestion caused by these crystals. Wearing gloves or washing hands can avoid toxic intake. Usually, the symptoms can be cured by thoroughly rinsing the mouth and drinking water or milk.

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8Mountain Laurel

Mountain Laurel

Mountain Laurel, also called calico-bush, is native to the eastern United States. The hexagonal-shaped flowers have a light pink to white color that usually grows in clusters. All parts of the plant are deadly toxic and can be fatal to humans and pets. Andromedotoxin and arbutin are the principal toxins and are dangerous and sensitive to the skin. 

The primary symptoms are burning lips, mouth, and throat, vomiting, abdominal pain, weakness, and low blood pressure. Children may get poisoned by sucking on the flowers. When the symptoms worsen, progressive paralysis can happen, followed by coma and death. So, wearing gloves and long sleeves is required when dealing with this shrub.

Honey made by bees from mountain laurel is highly toxic, and its consumption causes Mad Honey’s disease. The flower remains should be disposed of quickly to avoid close contact with children. Also, burning any part of the plant causes severe irritation and allergies to the lungs and skin due to poisonous smoke. 

7Water Hemlock

Water Hemlock

These small, white flowers grow in clusters and are usually found in the northern parts of America. The entire plant is poisonous, including its leaves, stems, seeds, and flowers. Consuming even in smaller amounts can be severe due to the presence of toxic alkaloids and can be fatal to humans and animals. 

Usually, symptoms appear after 30 minutes of plant ingestion. The severity can vary depending on the amount consumed and the growth phase. Alkaloids can cause respiratory failure by affecting nerve impulse transmission to muscles. Skin allergic reactions can happen even gently touching the plant. 

The flowers are usually found on roadsides and waste areas and can be dangerous to livestock. Fumes that arise after burning can trigger asthma symptoms. So, wear face masks,  gloves, and other protective measures to prevent an adverse reaction while interacting with the plant.

6Autumn crocus

Autumn crocus

Belongs to Colchicaceae family, the species is primarily found in southern and central Europe. The purple or pink to white colored flowers form tight clusters on the ground. Generally appears in autumn as a group of  5 flowers that can grow up to a height of 20 cm.

All parts are highly toxic. Colchicine is the primary poisonous alkaloid in autumn crocus and can interfere with cell mitosis. It affects microtubular-dependent cell functions by blocking mitosis in multiple tissues through binding to a tubulin protein. Acute colchicine poisoning may lead to multiple organ failure. It also affects glucose tolerance,  prolactin, insulin, and catecholamine production.

The typical symptoms are nausea, circulatory failure, vomiting, and respiratory paralysis. In the worst case, their consumption can lead to death. But no direct poisoning can happen due to close contact. Anyway, wearing gloves and covering mouths can ensure safety. 

5Angel’s trumpet

Angel's Trumpet

An ornamental herb that is distributed over Andes regions of South America, ranging from Colombia to Chile. The long trumpet-shaped flowers usually appear in pale orange to peach colors. A strong and sweet fragrance released by the flowers attracts moths and hummingbirds for pollination, particularly at night.

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All parts are considered poisonous. Since the flowers contain toxic alkaloids such as atropine, scopolamine, and hyoscyamine, their ingestion may cause disturbing hallucinations, tachycardia, paralysis, and memory loss. But due to its hallucinogenic effects, indigenous people in the northern Andes used it as a traditional herbal medicine.

Symptoms can vary depending on the severity. Intense thirst, vomiting, diarrhea, fever, confusion, and difficulty with speech and swallowing are some common symptoms, and in the worst cases, it may lead to paralysis, coma, or even death. So, proper treatment, including medication, detoxification, monitoring, and medical care, is needed to get relief from illness.

4Lily of the valley

Lily of the valley

It is a popular garden flower that usually grows in regions of Central Asia, the United States, and Europe. Flowering occurs in April and May as dense clusters under the shades of trees and shrubs. The tiny bell-shaped pale pink to white flowers produce a strong floral scent. And as cut flowers, they are used to make bridal bouquets.

The entire plant is highly toxic and can cause serious illness whenever it is consumed. The toxic compounds can severely affect heart functioning. Even though it is used in smaller quantities for medication, a sufficiently large intake may lead to severe chest pain, cardiac distress, and even death. 

Convallatoxin and convallamarin are the primary toxins present in the lily of the valley. But apart from these toxic glycosides, numerous other poisonous compounds like saponins can be fatal to young children and pets. Seeking immediate medical help is the primary solution to Lily of the valley poisoning. All symptoms may last for at least 3 to 4 days. 



An attractive flowering plant with bright purple, pink or rose, cream yellow, and sometimes white colors grows throughout the United States. Foxgloves are widely cultivated for their beauty in private gardens and generally bloom in early spring. But all parts of the plant, including flowers, are extremely poisonous. 

A mixture of toxic alkaloids, particularly atropine, in foxgloves affects the nervous system and causes severe symptoms like vomiting, sweating, breathing difficulties, hallucinations, and even potential coma and death. Usually, making tea and herbal medicines with foxgloves is not recommended since they are dangerous and life-threatening.

Measuring digoxin, a form of digitalis concentrations in the blood, helps to detect foxglove poisoning. Because digitalis, a medicine to treat heart diseases, is derived from this plant. Medication with a controlled dose of digitalis is one of the best remedies for treating heart failure. But an unregulated dose decreases the heart rate or causes irregular heart rates. 



Oleander is an evergreen shrub with pink, red, or white flowers forming large clusters in early summer. They are extensively used in highway landscaping due to their long-flowering nature and drought tolerance. But common oleanders are highly poisonous plants as they contain cardiac glycosides. 

Cardiac glycosides inhibit the regular working of the cellular membrane sodium-potassium pump, resulting in decreased electrical conductivity through the heart and eventually causing irregular heart activity, complete block of cardiac activity, and death. Even though the flowers are alluring, their accidental ingestion causes dizziness, weakness, confusion, and visual disturbances. 

Red flowered oleander varieties are more toxic. Its poisoning causes vomiting, severe heart rhythm disorders, nausea, and bloody diarrhea. Usually, most of the cardiac and gastrointestinal symptoms from oleander poisoning appear four hours after ingestion.

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Aconitum is a perennial, ornamental herb native to western and central Europe, having attractive blue to dark purple flowers. Most aconitum species are highly poisonous, so they have to be handled carefully. All parts are highly toxic. Aconitine is the most dangerous toxin among the toxic materials present in the plant. It is regarded as a heart poison and a potent nerve poison. 

Symptoms appear within a few hours after ingestion. The primary symptoms include slow or fast heart rates, numbness, and gastrointestinal manifestations such as vomiting, abdominal pain, nausea, and diarrhea. In severe cases, heart rhythm abnormalities and Respiratory paralysis can lead to death. Since no specific antidote exists, treatment is provided according to the symptoms.  

Raw aconite flowers are extremely lethal. So the plants are processed with extreme care to reduce the toxic alkaloid content. Steaming or boiling while processing converts the aconite alkaloids into less toxic or non-toxic derivatives. But inadequate processing makes the situation even more, worse by increasing the toxicity levels.