En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
1 rating

Saturday - August 24, 2013

From: Richmond, TX
Region: Southwest
Topic: Non-Natives, Poisonous Plants
Title: Does non-native Crown of Thorns cause cancer?
Answered by: Nan Hampton

QUESTION:

Does the plant, Corona De Cristo (Crown of thorns) cause cancer?

ANSWER:

First of all, the focus and expertise of the Lady Bird Johnson Wildflower Center is with plants native to North America.  Euphorbia milii (Crown of Thorns) is native to Madagascar and, thus, is really out of our purview.  However, I can point you to several internet sources where you can find out more about it.

Poisonous Plants of North Carolina lists it as being mildly toxic and, according to the University of Florida Miami-Dade Cooperative Extension Service:

"As with other euphorbs, E. milii produces copious quantities of poisonous milky sap that can cause skin irritation, and contains tumor promoting chemicals (diterpene esters).  It would be best to wear gloves when handling the plants, and to wash off any sap that gets on your skin."

Here is more information from Union County College in New Jersey.

There are rumors about the plant having cancer causing abilities and several of the sites listed above note that the sap has chemicals that are known tumor promoters.  However, a study testing the sap on mice skin did not produce tumors.  [Delgado, I. F. et al.  2003. Absence of tumor promoting activity of Euphorbia milii latex on the mouse back skin.  Toxicol. Lett. 2003 Nov 30;145(2):175-80.]

If I were you, I would use caution in handling the plant and, as the advice from Miami-Dade Cooperative Extension Service recommends—wear gloves and wash off any sap that gets on your skin.

 

More Poisonous Plants Questions

Native plants and possible poisonous plants in Aguanga, California
August 31, 2009 - I am in the process of moving to Aguanga California. I am interested in knowing what the native plants are in that area. Are they poison to animals and kids?
view the full question and answer

Are palm leaves poisonous?
August 18, 2008 - Are palm tree leaves poisionous? Because my dad was doing yard work and was stuck by a palm tree leaf in his calf. His calf has swollen and in he thinks it broke off in his calf.
view the full question and answer

Miami gardener needs to know toxicity of Cordia boissieri
October 12, 2010 - Hello. I have a question about Cordia boissieri. Is it toxic for humans (all parts of the plant)? I want to plant it in South Florida, in an area with children.
view the full question and answer

Identification of bush/vine with purple berries
August 09, 2014 - I was clearing fence line and came across this plant it looks like a Bush but underneath grows like a vine it has long broad leaves that reminded me of Polk salad but it grows berry clusters the berri...
view the full question and answer

Shrubs that non-toxic to horses but that they won't eat
October 29, 2011 - I am looking for a low maintenance, low water, green shrub that horses won't eat and will not be toxic to them. I want to hide my neighbors corral and keep down dust on my side. The horses have "l...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center