Is The Crown Of Thorns Plant Poisonous or Toxic?

The Crown of Thorns, also known with common names Christ thorn or Christ plant, is a flowering plant species from the spurge of family Euphorbiaceae. 

The association with Christ comes from the biblical account of Jesus wearing a woven crown of thorns, made from the stems of the plant, during the events leading to his crucifixion.

Flowers of the Crown Of Thorns Plant PoisonousPin

On the other hand, the botanical name, Euphorbia milii, commemorates Baron Milius – the individual who introduced it in France in the early 19th century.  

It is referred to as Coroa-de-Cristo in Brazil and Corona de Cristo in Latin America.

Native to Madagascar, it is one of the few succulents with true leaves and is widely grown. Because of its ease of growth and colorful showy flowers blooming almost year-round, both indoors or out.

While Christ thorn prefers warm temperatures, it can grow in colder climatic regions as a houseplant and is hardy to the United States’ hardiness zones 9 to 11.

Is Crown of Thorns A Poisonous or Toxic Plant?


Although Euphorbia milii is generally considered an ideal houseplant. However, you need to exercise caution if you are growing this species in your house, particularly if you have children or pets because it contains phorbol esters, which are poisonous. 

Ingestion of any part of the crown of thorns causes toxicity.

The sticky sap produced is also somewhat toxic and known to be a skin and eye irritant.

This Euphorbia is known to be toxic to humans, cats, dogs, horses, and sheep.

What Parts Of Euphorbia Milii Are Toxic?

All parts of the Christ thorn cause poisoning, in both humans and pets, if ingested.

In addition to this, special care needs to be taken while handling the plant because its injured stems and leaves produce a sticky milky sap, which contains caustic chemicals and irritants. 

Hence, it causes eye and skin irritation upon contact.

What Are The Symptoms Of Poisoning?

Irritation or blistering in throat and mouth, severe stomach or abdominal pain, and vomiting are the key signs of the crown of thorns poisoning. 

Some other symptoms both humans and animals may experience include emesis, excessive salivation, weakness, and diarrhea.

Upon contact with skin and eyes, the irritating sap causes dermatitis and swelling respectively. 

You may also experience intense pain, particularly if you have open cuts. 

The sap may also cause temporary blindness. 

Immediately rinse with water, if the sap mistakenly gets into your eye and get medical help if it doesn’t get better within 15 minutes.

In horses, Euphorbia milii may cause severe blisters and loss of hair on the ankles.

How To Protect Yourself While Handling Crown of Thorns

To prevent getting in touch with the sap, it is recommended to wear gloves while handling Euphorbia milii and discard them immediately afterward. 

To be on the safe side, wash your hands as well.

Also, be careful to not touch your body, eyes in particular, while you are working with the plant.

While this Euphorbia species doesn’t attract most animals, it is slightly appealing to livestock animals.   

Pets and livestock animals can eat the leaves of the crown of thorns when they are hungry and are not supplied with their regular food.

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