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 Non-Natives Questions

Texas native plants that absorb air-borne pollutants
December 15, 2008 - hello mr. and mrs. smarty, I'm looking for native Texas plants that absorb pollutants and trap air-borne particulates. I found a list (below), but don't think they're native. Could you give me ad...
view the full question and answer

Could ammonia harm poisonous, non-native oleander in Bay Point CA
December 20, 2009 - Could ammonia harm my Oleander plant? I have been spraying ammonia under it to keep neighborhood cats from using the soil under the plant as a sand box. If so, do you have any suggestions as to what...
view the full question and answer

Non-native astilbe resemblance to non-native poisonous castor bean from Tomslake BC
May 21, 2014 - I have a plant that looks like a castor bean but it has flowers like a Younique Silvery Pink Astilbe. Need to id because castor bean is poisonous. This plant grows up to 5 feet in height. Thank you !
view the full question and answer

Possibility of replacing Bermudagrass with native grasses and wildflowers
November 24, 2008 - Are there any native grasses and wildflowers that can compete with bermuda grass to make a nativ-y wild area without removing the bermuda?
view the full question and answer

Toxicity of non-native red-tip photinia to fish from Friendswood TX
April 10, 2013 - Mr. Smarty Plants, I have seen several questions on Red Tip Photinia (RTP) concerning toxicity to horses, dogs and children. We recently lost over 100 gold fish and 6 large KOI in our man made back ...
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