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

Trimming Texas mountain laurel in Austin
August 27, 2009 - Is there a specific time to trim established mountain laurels? Should I cut off the dried seed pods since they are weighing down the branches?
view the full question and answer

Do palm trees put off a toxic smoke when burnt?
December 09, 2008 - do palm trees put off a toxic smoke when burnt
view the full question and answer

Plant ID of unknown purchased plant from Boise ID
June 24, 2012 - Hi! I bought a tree that the sales person didnt know what it was. I thought it was a cherry tree and now after about 3-4 yrs I know it is but..How do I know if it is an ornamental tree or real fruit t...
view the full question and answer

Plum trees (Prunus spp.) poisonous to horses
June 08, 2008 - Are fruitless plum trees poisonous to horses
view the full question and answer

Reaction to something in the garden from Dowling MI
May 25, 2012 - In late March I was working in my yard raking etc. The next morning I had three black spots between my knee and shin that were swelling and feverish. Two days later the areas became bigger and began...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center